I definitely think that a minimum and maximum number of heroes per role is the way to go. I had a thread about this a while back. I’ll link it in case you are interested in the specifics.
Honestly, every role needs at least one and no more than 3. Quad anything comps are not fun regardless of what role has 4. And any comp without a role, regardless of the role, invalidate an entire class.
GOATS may be meta at the pro level, but quad DPS or sometime even more, is reality in quick play and lower ranks. Both are unhealthy.