Opinion on ac 2h vs 1h/shield

[Troxx]

From a mitigation standpoint I know that at high levels of gear based ac a shield is near-always preferable because it adds 1:1 to the ac hardcap.

This question is a little more complicated so I wanted some opinions. My 54 paladin just finished Natures Defender which rocks 45 ac. My paladin’s gear is fairly good did his level but only buffs to just over 1k. I don’t think I’m yet at the actual cap for diminishing returns.

45ac 2hs vs sword (no ac) and board (25ac).

2hander will eat fewer ripostes but for mitigation which do you wager is more potent given the rough gear/ac/level for this Knight. The would like to just assume 45 non-shield ac is better than 25 shield ac.

Thoughts?