All heroes can be really good, if properly forged (assuming everything else is max, like powers/units). You can base your “plan” on your style and the hero. But the fact is, that some heroes, are inheritable better, and need less forging, or less super forging, again depending on what style you use. In other words, it can be easier to build some heroes than others, naturally we then call them “good” and those who are “naked” in the same situation, are called bad.
I’ve been doing 12 skulls with Artemis lately. I have not super or max forged her, but I have done good work on equipping her how I play. I use some gems on corners, but she doesn’t die as much as I thought she would (I think she died 1-2 times on 15 islands). Been also getting her 1-2 times per week, lately… I was kinda lucky the previous months, I think I didn’t get her for a long period of time. And now, she is ready to at least get the 12 skulls, so no points lost on fame.
It’s not easy to balance all heroes in the same way, but essentially, all heroes should be equal. I believe that’s the usual intent of the devs in all games. Some heroes require different kind of setup, which is actually proving that the game mechanics, work pretty well… You can’t go with the same setup on all heroes.