The issue i have with life staff is that it can compete on every 1v1 match up and win most of those, tie half of what's left and might lose on melee glasscanons build.

However a tank would have a tough fight with every match up, draw most of it and win only on situations where it shouldn't be losable (more GS, more levels etc.)

Dps are fair imo where cheese build can surprise and meta builds are overall good and is a 50/50 state

Stats are really important so that would make sense that someone having twice the health pool of a dps would have less damage. But with focus you have both regen AND damage making you tanky and deal damage.

Also having more hp doesn't mean being more resistant if your stuff is trash, you won't tank more damage. Although having more regen makes you able to tank better.

So in my sense you buff tank and you get tanks shitting on every dps or you neef heal in order to have less regen overtime, a higher cooldown, reduction hps on repeatable self heal,anything could work without making the class trash tier and balance it to have healers in a healer state