Played against Extreme AI, 4v4. Played as Britons, flank position. Managed to kill a Celt enemy next to me, but later, the Tupi AI sent mass of Blackwood Archers at me, obliterating my forward base and longbowmen.
Play them and find out
In general Tupi don’t like to deal with Siege, Ranged units and mobility.
If you have a CA civ this might be the ideal time to try go for them when you face Tupi.
In general Tupi are a very strong civ in the current timing-based meta and probably need a nerf at some point. But I guess the listed weaknesses of them above will still apply.
Play with Bohemians on Arena.
From what I’ve seen, all the strengths and weaknesses of generic archer units apply to blackwood archers to a greater extreme. With the caveat that blackwood archers are better against battering rams (and probably Warwolf trebs as well). Blackwood archers do seem like a strong unit to me, but I don’t think they’re more OP than the other strong UUs in the game.
Basically, anything that would kill arbs will kill blackwood archers even faster. If you get melee units in close, the blackwood archers will die extremely fast. If you hit them with AoE attack, the blackwood archers will die more consistently than normal archers. But if you aren’t in a position to kill, the blackwood archers will also cover your troops with more arrows than normal archers would.