Builders are already made so that you're forced to pick and choose. A mag isn't supposed to be able to get every single upgrade. A morph is supposed to choose between support and basing. Nat is supposed to choose between hunting and basing.
Games in which you get every single upgrade are very one-sided and not typical at all. This builder will end up being useless due to high gold costs.
your first point, in which they don't get every upgrade, is partially true. In most pubs, you either get every upgrade, or the titan gets an early mini(within 70 seconds). But for the sake of argument, lets say you get 70 gold, then 2 people die for whatever reason. Now a mag can get polar. A morph can get beast form. A tauren can get rage. They could get 2 hp upgrades, or merch summons. This orc can get hp upgrades for his person, his walls, or he can get armor upgrades for his person or his walls. He has higher damage than the other builders at start, and he can get hp easier than the others. So he doesn't need the gold anyways. He levels up from attacks, so trapping the minion could almost be used as a feed for him. This builder is next to never useless, and if implemented i'd much rather have him than a tauren, but i'd rather have a mag. If attacking a mini i'd rather him than a mag, but not over a tauren.
