You do realise that this is a holotable game right? If you want a proper star wars rpg play Knights of the old Republic or the newer uprising game. This one is supposed to be simple and fun.
They've taken 75 characters and made about 80-90% of them usable which is pretty balanced. Your tiered system would only lead to them making the game less enjoyable as there'd be fewer heroes. Nobody would bother gearing a tier 5 ewok. If the game only stuck to characters you personally class as heroes we'd probably have less than 20 characters and a very dry game.
In order to create balance some heroes need to be healers some attackers some tanks etc and those roles may not necessarily fit in with how you remember them from the movies but it makes a fun game. If you want lore - I watch the movies. If you want a quick fun game - play this
