I'm intrigued by the idea. Personally, I'd make it so that it allows specialization at the cost of battalion size. What I'm thinking is that the ratios aren't the same both ways: For instance, trading away 10 manpower could give you 2 fuel, but trading away 2 fuel would only give you 4 manpower. (In other words, the trades are always "bad" in the sense that you don't get an even trade, but they can still be worth it because they allow you to specialize more. As you increased in rank, maybe the ratios could get better, so that a lvl 9 account wouldn't actually have more resources than a lvl 1, but it would be possible to deviate more from the standard resources. Of course, there would also have to be a maximum amount of resources that could be traded. Maybe it's a better idea to just increase this limit instead of making ratios better.
I'm just toying with the idea here, it might end up being a poor idea altogether, but how about something like this: All resources have a "buying" and a "selling" price, where you sell points below the start point and buy points above it. As an example (with numbers just chosen for simplicity)
With the starting point at 8000 MP, 2000 MU and 1200 FU (I forget if that's the actual numbers these days, but that's not important), you could for instance end up with
- 7800, 2050, 1200 (200 MP sold, 50 MU bought
- 7820, 2000, 1230 (180 MP sold, 30 FU bought
- 8150, 2000, 1100 (100 FU sold, 150 MP bought)
- 8050, 2050, 1100 (100 FU sold, 50 MP and 50 MU bought)
Once again, these numbers are not meant to be representative, just an example. If this was to be implemented in any form, a lot more thought would have to be put in it. And, as stated, I haven't thought about all the pros and cons of this idea. The things that immediately struck me as good about it, though, are these:
1) It allows for making tweaks to your company (missing 10 muni for that upgrade, but have 100 spare fuel?) as well as larger-scale changes (don't want to focus on tanks but feel that you're forced to buy 4 to spend all that fuel?).
2) It means that a lvl 9 company doesn't get a flat bonus over a lvl 1 company, but still rewards the lvl 9 company with increased customizability.
3) While somewhat complex, a new player can ignore it without any big disability.