Interesting. Got hooked when you mentioned natural selection, had played with the thought of doing something similar for some years now. But never came around to it. I have thought alot about its design though, but the actual making... im studying so dont have much time anymore. Made a bunch of maps though.
Let me give you some tips though: I assume you want two race sides, like zerg and terran?(or protoss aswell) Throw the hero idea out the window. Scrap it. Its an outdated model and thought process that is still stuck in your head. You said you thought about making them start with the basic unit again when they died, then what sense would a hero make?None. People want to dominate someone else, sc2 doesn't ahve heroes, and people play it. Spells, economy etc. is okay though. Maybe make heroes, but only if that is were the game is going, dont force the game into a hero game from the start.
Take blizzard for example, they're making their new moba, and don't have any gold farming. You can argue all day why blizzard is so dumb lately, but they're on to something, you can't copy to get to the top. You need to find a new niche. Add heroes and you will always be in the shadow of others.
Keep it pure. What is the pure core of this idea? Take natural selection again. A platform, maybe a ship, two sides gaining ground on each other, a fight between economy for later strength and here and now power, but later weakness, and the winner is decided on skillshots and multitasking. Thats it. Thats the core. Go from there, not kerrigan, not heroes, you work your way up, from the roots, not the leafs. If you dont, it will come across as cheesy, as clunky, unfinished, as if its lacking something, it maybe even look incredible good, but after 2-3 games people will just not want to play another round. And they don't know why. To avoid that you have to find the interesting core first, instead of the superficial. Thats my experience through the years.
Well I would be interested in working with you, but honestly terrain and game design is the only things that interest me, and which I have time for.