Riot you need to decide if Tahm is a juggernaut or support and remove things accordingly.

Having the damage of a juggernaut and the utility of a support is making him extremely oppressive for most top laners and he is basically impossible for most melee to even trade with due to that 3 hit stun.

Just examples of what could be done:

If he is a juggernaut then get rid of the 3 hit stun (perhaps have it be a half second slow if you refuse to remove it fully)/reduce the duration of Devour to 1 second on enemies.

If a support get rid of the shield /remove the 1.5% of his max health on hit passive.