Would you, creators of this fine game, be interested to have us, your loyal subjects, send you designs for maybe new troops?
Maybe make a competition of it - the reward of having a troop that we designed would be enough reward. A few keys or gems would also sweeten the deal 
Usually there are legal IP issues that the company lawyers first have to iron out.
That doesn’t stop you from posting in the forum though. Enough of us have already got threads going with ideas 
Dang! I was looking forward to send in my stick figure knight 
LOL, but I get your point melkathi
In the Feature Request forum, you’ll find a TON of great ideas for troops, some by our favourite Mel actually.