How much do troops and talent emblems affect a hero's performance?

I am working up the ladder with my heroes. I’ve strengthened the troops, too. And some I’ve decided to add what I can to their talent level. My question is, do these ancillary elements of troops and emblems really make that much difference to the hero’s overall performance?
I’m willing to say that perhaps the true benefits do not really show until you have 4* troops level 30 and a full talent grid. Am I mistaken? Feel free to explain the benefits to me.