How many pieces of gear are there, really, that outperform the humble +2 armor and +1 shield?
This means +2 studded leather for light armor, +2 half plate for medium, +2 full plate for heavy.
Wyll and Gale are conveniently human and could just set up on +2 studded with +1 shield. Astarion can also studded +2.
Karlach and Shadowheart could use +2 half plate, though it is likely only Shadowheart that wants a shield.
Of course Lae'zel can use the mighty full plate+2.
But if you compare full plate+2 to adamant splint armor, which is only ac 18, what wins? How about flawed Helldusk? Etc.