To a degree yes, but the fleet research forces you to either take care of your ships, or build a huge economy to support replacing them. Either way it makes replacing huge losses difficult, rewarding the player who managed to engineer their destruction. The way fleet capacity functions in the game is fine just the way it is, and the things suggested here would completely change the way the game is played. Flat rate per upgrade is poor idea because, as the OP stated, planets become too valuable. A player could simply wipeout enough of your economy to put you in a hole you could never recover from, because destroying things tends to take much less time than building them. All i have to do is put you in the negative and then wait long enough for your resource reserves to deplete. Then you're dead. With a percentage, negative income is highly uncommon. If it were a flat rate per ship, then again, as stated before, a players economy grows stronger as he loses ships, making them easier to replace. The game would get nowhere, and would probably turn into a total spamfest of the best ship for your buck, either lrfs or HCs. Eitherway as also stated above, fleet capacity mechanics are not going to change. Perhaps a modder could figure out how to make that kind of game for you. But I'm 100% certain the gameplay wont be anywhere near as fun as it is currently.