His reworked passive is actually pretty similiar to the live one.
We don't know what changed, but it is similiar to Gem Craft.
Atm his passive is actually the only thing that keeps him a bit "complex", because it's the only thing you really need to worry about.
I find it pretty neat managing your cooldowns while also dealing a % of your armor as bonus damage.
If played right you only run out of mana, not cooldowns which i think is a pretty solid and supportive passive.
Remember, lower cooldowns= more heals for your carry= good sustain.
And just don't worry about clunkyness in Tarics kit atm, his rework is not too far away (will be revealed after Aurelion) and most of his clunkyness should hopefully be fixed with his relaunch. The real problem he has is that his Q, W, E and R are absolute lackluster abilitys with outdated animations, real simpleness and only very minor uniqueness.