You're going to run into commander problems pretty quickly I think. A 25,000-ton total formation built out of 25 1,000-ton sub-formations is going to need 25 ground forces commanders, and one usually starts a campaign with around 50-60 of these. Granted you generate more over time but once you start having more than just 1-2 "planets of consequence" you'll need an awful lot of commanders and this is before you even start planning your offensive forces (which regularly need to be in the 100,000s if not millions of tons to take a planet).
I originally made every company almost exclusively out of Static Heavy Weapons since why not? I figure if an enemy attacks my planet I'd much rather keep them occupied in a protracted siege until I can relive them with outside forces rather than risk losing the garrison and the planet in a counter-attack. But I thought it was kinda unrealistic how the entire garrison was made of heavy weapons only and some infantry, and was worried that the relative lack of 'shots' the garrison could take would lead to it being overwhelmed. So a typical PDF battalion has 3 standard PDF Infantry Companies and 1 PDF 'Strongpoint' with all the Heavy Weapons wrapped in Heavy Armor.
The main issue with heavy weapons is that they are very often overkill. If the enemy lands just INF and VEH for instance then MAV would be fine to kill the VEH (at equal tech) and HAV is overkilling them thus wasting tonnage that could be given to more guns.
A general principle of Aurora ground forces is that offensive forces should be optimized for tonnage efficiency as transportation is the limiting factor in their deployment, but defensive forces should be optimized for build-cost efficiency as transportation is usually not the limiting factor on defense. In practice of course once can easily out-build their command capacity especially early on, but later in the game when it becomes necessary to continually upgrade forces to the latest models command capacity will catch up - doubly so if your base formation sizes also grow over time as while one might begin the game with 5,000-ton battalions, as troop tonnages reach into the millions larger base formations become more practical.
Thus for defensive forces, you usually don't want to think in terms of deploying the heaviest weapons you can, but as many as possible of the cheapest weapons that will (probably) do the job. Not only does this often mean using MAV, MB, MAA instead of HAV, HB, HAA but also using less than the maximum armor on your static weapons (trusting in fortification and base HP to do most of the work and assuming that a weapon which overmatches your HP will also overmatch your armor anyways).
As a last aside, your STOs probably do not need HQ elements as they do not benefit from the ground combat commander stats except for "Tactical" which does not seem to be common and most commanders will have other stats that benefit your ground troops who need them anyways while rarely does an outcome hinge on getting that extra 5% out of your STOs.
