I do feel like bmb brought up some really important things about how we would like CAP4 to perform and others on here ahve also brought up that we do need some way of getting the reward that makes up for the risk that we have created with alot of common weaknesses and the stealthrock weakness.
Someone also brought up the fact that bug buzz would be the strongest move against t-tar which I personally feel should be at least a 65-35 in CAP4s favour. This means that we should probably go with a physical set with megahorn as it's main stab. If this is the route we would take I feel like CAP4 would need a "high" attacking stat cause if so a Megahorn/Zen headbutt (yeah I know there is nothing better this far...) Would be able to deal alot of damage even if it's resisted (base 130 atk adamant megahorn 2-hits standard ferro on the switch and the same set OHKOs standard Tentacruel with Zen headbutt)
If U go physical though pokes like: Forretress, Scizor, Skarmory, Heatran and Genesect would completely wall CAP4 if we don't give it a coverage move (I would suggest fighting in this case) since going with hidden power fire/ground won't be as effective as if you used a special set. I have a feeling though that people are gonna go full support for a special QD set.
Sry if I went to much into moves/stats but I just really wanted to analyze what counters we would get if we decide to go with a physical set.
also sry for my english it could be a bit better (Swede)