I think it would be cool if there was a Sandbox mode where u had Infinite money to try any formations out and could even do multiple of any crusader so u could have like 10 Sashas or something.
And you could do areas just the same as normally except you would not gain any chests obviously

its a mode where u could try out different strategies without having to worry about the cost...plus i personally think it would be cool to see how much DPS you could get if u were able to use the same person more than once