Like Spirit said, the game is about choices and options, and play according to what you need. But when you don't have other choices, you need to play with the best you have.
As Imperial Level 10 I don't need to win any attacks anymore. I don't play conflicts, events, wars, neither do objectives. I attack only for loot for upgrades, and on Tatooine over the richest Rebel bases I find. The eAT-AT to destroy 1 shield or 2 over the Safehouse only to bomb it with a Tie and leave, it's fine by me. Kubaz to infiltrate a non-walled base and find a hole where i can deploy Lord Vader and his friends and try to loot eveything I can, it's fine by me.
As Rebel Level 10 I also don't need to win any attacks anymore. Same game experience for this account, attacking only for the loot to pay upgrades. My Kessen sniping a SC probably full of Rodians or Jumps or whatever, and my Jets killing Rodians or MHCs or whatever on battlefield it's fine by me if I can get all loot I need.
That is my experience. But when you need to win attacks, and win by 3 stars, heroes aren't an option, they are necessary. As I said, if you want to have better heroes you need to get the skins for them in conflicts, events, objectives and keep chasing crates for one year or more. Or try to adjust to what you have, because all new heroes introduced in the game after Armory, are by frags upgrading and pure crap...
eAT-AT and Kessen are the only heroes useful for Imperials (while Kessen for Imps have only 5min cooking time). But Kessen is a data frag hero, and not everyone is able to get frags for his upgrades, and Kessen still is the only useful hero for Rebels but with a cooking time of 10min. That's the problem. Reducing this time for Rebels already would be a good upgrade if you have your Kessen at high levels.
A Windows survivor now training players and helping squads through the Galaxy!
Imperial HQ10 in "BombSquad18" (Level 49 squad)
Rebel HQ10 / HQ8 in "Ewok_revenge" (Level 50 squad)