not really. isn’t it the same in Gems of War, when concentrating all efforts on traiting a new legendary by all means?
and as soon as my workhorses will have reached a decent strength i can turn my attention to the more fancy units again.
i’m ok with it, and making steady progress without spending real money.
i only bought the x3 value pack (5,49 euro) for once, out of respect for the developers having done a good job.
in Hero Arena i’m #60 in the Grandmaster league now, struggling for promotion (position 1-50). my 5-5-5-6 team always battling against higher leveled opponents’ creatures.
very satisfying to squeeze out a win.
btw a highlevel Elfling with upgraded abilities is a true monster.
one of my most feared adversaries. he can hew down whole fields of units 
another tip is the common unit Rotbite. great synergy with other fast attackers.
he can overwhelm much stronger opponents and barriers.
it’s fascinating that there is not THE best unit for each color.
different teams can all be good.
for not littering this thread any longer i have created a Solgard thread.