I have over 400 counter on one of my heroes. I am regretting it, but I've went to the trouble of adding two counter skills, which one of them is Backlash 3, that is for units as well as my other hero counter skill.

I hardly ever counter. I have mele units assigned, and he get's hit often by all incoming mele strikes. He only seems to counter like, 5-10% of the time. Totally not what I expected from counter. Does it get any better than this, or did I just waste all that effort and faith in counter?

I typically don't go for Backlash or Vengeance on my Defensive heroes due to the way that tanking weapon are they don't have a lot of attack. Barks are the best tank units and don't have decent attack either. Bandits don't do too bad as tanks and have high attack where counter can be beneficial on them. So typically for a defensive hero my skills go:

Guardian Will I-V
Dragon Skin I-V
Fortitude I-V
Entrenchment I-V

For the four major ones. Then the next ones to use is:
Acclaim I & II

More units = always better.

For the 6th one for Defenders you could go backlash or vengeance but I like my defenders to be able to survive over do damage.

So I tend to choose either Shadow Master I & II or Swift Mover I & II for the last one for Orange+ heroes.

Hope this helps.