This game has a lot of different builds you can do, death, archer, mass units, firemage, tank, ninja, summoner (needs buffs) etc etc. 

I think each of the pre-made characters should clearly demonstrate one of these builds (and a couple hybrids that choose 2).

There should be a sentence describing this focus so the casual player can know what to expect and what to build towards.

In addition they should get 2 more character points than the costum made characters.

When I build my own faction I take 3-4 weaknesses and I always take the best options in each category. It would be more interesting to play the pre-built ones sometimes and increase the longevity of the game because each one shows off a different strategy.

Then once people understand all the different strats and builds they can make their own combination of the builds.

Mike.