From the 1. 13 patch notes:

- Fixed bug that meant that strength required to force populations to surrender strength was 100x more than intended.

Does this mean the fix hasn't been implemented yet?

I had only 10 troop transports and 8 armoured brigades each of 1 x HQ unit plus 4 x Armoured battalions plus about 4 infantry brigades and 8 garrison battalions, about half the armoured battalions were the then new heavy units. once the initial slaughter of the landing was over it was the heavy units which vanquished the aliens as they found it very difficult to penetrate their armour. I did pillage my mining companies and gained another 13 garrison battalions.

If I had double that total amount of "police units" they would have evaporated. I was facing at least 45,000 to 50,000 enemy units, most were infantry although there were quite a lot of STO units which I took out by orbital bombardment (rods from God). I defeated the aliens with a force which at the finish had an occupation strength of less than 700. To force a surrender I required an occupation strength of 85,244 but once that was achieved as it reduced to 10,250 and SMing a lot of basic infantry the police strength required was only 44, the population down to 73 million.

Yeah, the forces you want to deploy to smash the enemy army and the forces you want to deploy to pacify the locals are pretty different in general, you always want to have some big bulk carriers that can ferry large amounts of cheapass garrison soldiers to police things once the dust has died down.

So, I've just been looking at my garrisoned forces and their police strength, after reading Meowth's comment:

Quote

The idea is that a tank is better than a grunt for suppression, but not linearly so (hence the sqrt). Between an equivalent tonnage of tanks and smaller units, the smaller units are more effective because they can be in more than once place. This gives an extra purpose to light personal weapon infantry too (cheap, small units for occupation).

I have a 2500 ton Infantry brigade on one world made up mostly of infantry with light armour and improved personal weapons at size 6 per unit, plus some specialist infantry.

On the second neigbouring world I have some garrison batallions totalling 2500 tons. They are mostly made up of my "military police", infantry just carrying light personal weapons at size 3 per unit.

The first world has 236 total ground units providing 8 police strength, the second has 566 total ground units providing 14 police strength. So more, cheaper units provide almost double the police strength for the same tonnage.

I thought this might be useful to know, if you didn't already. It could make it a lot quicker and cheaper for you to field a pacifying force for that alien homeworld, rather than sending all your high tech ground units there which will be a lot less efficient at adding police strength. Of course my "military police" are really just cannon fodder if anyone decides to invade a world with them as the garrison.

Yes cheaper units would be better for policing but that was not the only problem. I found this world approximately 25-30 years in. Having gone through a couple of mineral and wealth crises I had only just begun to expand my navy having found a precursor system with a fleet that was at least double or triple my existing fleet. I then ran across the aliens only two jumps out and after a couple of months squabbling over possession of that system they blew away my diplomatic ship.

I had only 10 troop transports and 8 armoured brigades each of 1 x HQ unit plus 4 x Armoured battalions plus about 4 infantry brigades and 8 garrison battalions, about half the armoured battalions were the then new heavy units. once the initial slaughter of the landing was over it was the heavy units which vanquished the aliens as they found it very difficult to penetrate their armour. I did pillage my mining companies and gained another 13 garrison battalions.

If I had double that total amount of "police units" they would have evaporated. I was facing at least 45,000 to 50,000 enemy units, most were infantry although there were quite a lot of STO units which I took out by orbital bombardment (rods from God). I defeated the aliens with a force which at the finish had an occupation strength of less than 700. To force a surrender I required an occupation strength of 85,244 but once that was achieved as it reduced to 10,250 and SMing a lot of basic infantry the police strength required was only 44, the population down to 73 million.

I found it difficult to work out what an alien battalion consisted of as in pacifying their home system all their mining bases have 4-5,000 infantry, 20 each of AA & AT teams 10 AA vehicles and 16-20 STO units plus HQ units. I don't know about you but building STO units takes me forever. I have just found a new alien planet with a ground force of 41,500, they took out my survey ship with STOs. The nukes are on their way!

As an aside I would have been better off nuking the planet as the ground combat went on so long the planet had been wiped clean anyway, might have been a few installations left.

I think you are underestimating ground unit occupation strength.

The formula is precisely sqrt(element size)*#units*morale/10000

The words "element size" and "units" are key. An element is a single ground unit, like an infantry or a vehicle. # of units is not the # of formations, but the number of infantry or vehicles.

The idea is that a tank is better than a grunt for suppression, but not linearly so (hence the sqrt). Between an equivalent tonnage of tanks and smaller units, the smaller units are more effective because they can be in more than once place. This gives an extra purpose to light personal weapon infantry too (cheap, small units for occupation).

Thus, a battalion of 1000x6ton infantry with 100 morale has an occupation strength of sqrt(6)*1000*100/10000=24

Not sqrt(6000)*100/10000=0.775 as your calculation would suggest.

Yes I suspect you are right, If I look at the occupation strength of my forces on the planet it looks about right. In that case I only needed 3552 battalions. That's a lot better than my initial estimate but still way more than I had or have. Still think I should have glassed the place!

Thanks to all the dust kicked up in the months if not years of fighting the population has reduced to 73 million and with SMing approx 400 infantry battalions in they finally surrendered. The planet went from a colony cost 0 to 4.7793, all without the use of nukes.

Thus calculating back the population would be about 630 million. There are no installations but large amounts of fuel and maintenance supplies. so I don't know whether this was a colony world or the home world! Although the presence of 788,600 tons of naval shipyards and 1,857200 tons of commercial shipyards hints that it was the Home World.

Edit: I think there is an error here as the police strength required is 44!  Has anybody else found a planet with >39,000 infantry and many thousands of other units? This planet had. I think I only conquered it because it could not maintain its ground forces.

While I can only assume this is working as intended it makes conquering an alien population almost impossible!

Current Example

Total Pop capacity of planet 20.815
Assume Determination, Militancy and Xenophobia are all 100 and pop is maxed out ( game is 35 years in so unlikely, Earth pop is 1818.2 million)
Political Status Occupation Modifier = 1 (conquered)

Thus  (Determination + Militancy + Xenophobia) / 300  * Population Amount * Political Status Occupation Modifier (conquered) = (100++100+100)/300  * 20815 * 1 = 20815

occupation strength = (SQRT(Size) * Units * Morale) / 10000

Using an infantry battalion of 10722 tons and morale of 100, Square root of size is 103.55 approx

Therefore occupation strength of 1 infantry battalion is 103.55*1*100/10000 = 1.0355

Thus required occupation strength should be 20815/1.0355= 20104.4 infantry battalions. (which I don't have).

However I must have made a  mistake as the required occupation strength for this planet is 85,244 equivalent to 82,322 of my current infantry battalions !

 I should just have glassed it!