It’s funny you mentioned this, because that’s exactly what I’ve been doing with my roster for the past eight+ months.
Rather than spending mats on heroes I suspect might be good, but I haven’t played with them enough to know if I [personally] like them, I have been leveling all of my 3* until they’re 8/8 skill, 4* to 3/60, and 5* to 2/60 (some 3/70 if they really interest me). Even the ones I know are bad I’ve been leveling, because I want to find a use for every hero, and don’t like the idea of having all of these 1/1 unique heroes never being touched. I currently have 90 unique 4* and 5* I’ve been doing this with, and have completed all but 12 (so I’m almost done).
Out of all of this, you get variety, plenty of choices for color stacking, play around with different synergies, and make use out of nearly every single hero at least once.
Also, it helps me know what stages of the game are beatable with underpowered heroes. Thankfully, I’ve been able to complete everything in game, including all quests, events, seasonal events, and trials, since I started this. I have zero maxed heroes, and have still been able to sit in diamond, get B or higher grade on 10*+ titans, and hold my own in war.
You never really worry about mats either, so you can just let them accumulate. By the time you’re done, you’ll have all of the materials you need to max most of the heroes you decide you want to. I have enough mats to max almost three rainbow teams of 5*, and over 50 4*, but I enjoy leveling my heroes to the ‘half-baked’ point, and playing around with them for a bit, first.
Plus, all of the information I learn from playing with every single hero, I get to share with the people on this forum and within my alliance. So idk it works really well for me, and I enjoy it.
The only downside to this style of play is you can’t really compete. If that’s your goal, then I’d suggest maxing the best of the best heroes first (starting with a few rainbow teams of 3* and 4*), and then building out your depth from there. Trying to place on the leaderboard for events, weekly raids, or regular raids isn’t doable with half-baked heroes.
However, if you decide to go the route that I have, just know that you should be alright when it comes to completing everything in-game. Just have to be smart about your lineup and battle items choices for certain events, but everything should be doable with mostly 60s. Might want a few 70s though ‘just in case’.
Honestly though, I’d go with the option that you think you’d enjoy the most. At least, I know that’s how I decided. Do you love playing with a bunch of different heroes or finding fun uses for certain ones? Or do you like competition or wanna be the best at something? Do you love variety, or playing with the same favorite/best heroes day-in and day-out?
Really think on it, and then decide for yourself
Makes the game way more enjoyable when you find your own preferred way to play, even if it’s not the norm or what you ‘should do’, as long as it’s fun to you