This is a pretty simple request, it doesn't require much beyond the addition of some text and an extra column in a table.
Problem: Right now ground units and transport of them is a very muddy subject for a new player. The game uses three different ways to describe ground unit sizes and it uses them inconsistently. For example:
1) Transport and drop modules (in the research window and the ship design window) describe it only through terminology; as battalions and companies, etc.
2) When functioning as transports, the task group displays the contents of their modules using the actual manpower number. 10000, 25000, etc.
3) In the ground unit creation window, the unit title includes its terminology (battalion, division, brigade), and is also described by its component size. 5, 25, 50.
4) In the existing, active ground unit window, the unit is not given a size whatsoever. There is no way that I am aware of to find out what size an existing unit is other than to go to the creation window and check.
My suggestion is to provide more information.
1) Transport modules and the ship design window should simply provide all relevant information.
'Provides enough capacity to transport a marine battalion. (Size 5, 1000 marines)'
2) I'm not sure if anything can (thanks to companies) or needs to be done in the task group window, as long as the other needs are met.
3) The ground unit creation window tells you the size as well as the terminology for the unit (in its title), which is probably sufficient. Potentially could could put the manpower number next to the size; Size 5 (1000 Marines) - but it's probably not necessary.
4) In the active ground unit window, for some reason the terminology is stripped from the unit (at least the starting ones). Instead of '2nd Low Tech Infantry Division' you just get '2nd Low Tech Infantry' and there is no displayed information regarding its size. With pre-existing units you cannot determine its size through terminology, size number, or manpower count.
The real issue comes when you are creating your first troop transports. The module tells you it is good for one battalion. You look at your existing units and it doesn't tell you what they are. There is no indication that you are going to need 10 troop transports to move one of your existing units. You pretty much have to fail, scratch your head, and start searching the wiki and the forums. And as I have discovered that is not always a wealth of accurate information.
Granted, once you figure out what size everything is it's trivial, but for a game that seems to delight in giving you information, ground units is one area where the details are murky, over-complicated, and under-represented. It would be trivial to change some of this stuff, so y'know. It'd be nice.
Thanks!