It is only misleading if it was asked to have a specialization. Only if you are for example out to have as much construction points as possible, you will get x10, otherwise it will always be less. Here it was asked for Construction and Mines, so that means x5 efficiency at max. already. Yet, if you convert a start pool of 1000 CI into construction and mines only, you will eventually recognize that you are not producing any fuel anymore, because those 1000 CI equaled 100 fuel refineries too. If you arm your crafts with missiles, then 100 ordnance will be missed as well. Fighters might only be feasible later.
If you convert all the 1000 CI equally into the 5 industries, you will only end up with x2 capacity - anything else is in some sense scrapping other factories to gain advantage in a specialized area.
I usually convert 10% into ordnance and 10% into refineries (just for the start) so that I at least retain the initial capacities of the CI. 40-40 then goes to equally mines and construction, though that might not be the best ratio. I end up with x4 the capacity.
Good to know that with the tech though. Conversion is a must.