The best setups involve having minimal areas the enemy can bait from. And within that minimal area the enemy can bait from, have multiple unit types able to attack it.( Ex, the one spot I'm able to bait on on your map puts me at risk from attack from blue green and red enemies, or a succession of enemies that guarantee to get a kill.)

This ensures the enemy will have to sacrifice at least one enemy to progress the battle if they don't want to bum rush you(which usually involves them sacrificing a unit anyways).

Your Tharja may be strong, but she's too prone to being baited and tanked by a common blue. Have someone that can kill blues also within that range to either finish the job or discourage the enemy from starting there.