160x128 (left) is what I settled on. 192x128 (right) was too big.
I looked closely at the DotA template and created hero selecting inns, placeholders for all 12 heroes, 8 custom creeps, the outpost/gate spawning system, and a bunch of creep routing triggers. I really like how productive I can be in this editor, even though I am still just learning the ropes.
After a few iterations to balance the creeps out, it became very apparent randomization of creep routing really hurts the experience. One of the cool things about AoS games is being able to rely on the predictability of creep patterns.
Next pass I'll focus on the gate-creep spawning + routing paradigm to make it a more interesting and integral part of the experience. Some other things I'd like to do after that include playing around with hero navigation, hero powers, advanced creepage, and upgrades.

Some pics of the fights in my latest testbed

Lots of triggers so far!
