There are 28168 possible teams, according to this line of code:
Total[Times @@ # & /@ (Subsets[Range[41], {3}] /. Thread[Range[41] → Flatten[{Table[1, {29}], Table[2, {8}], Table[3, {4}]}]])]
In the upcoming Blade event, there are 1520 possible partner sets for Blade.
In order to promote diversity in PVP, incredibly rare teams should get an autobuff. Each time a team enters, the servers would increase a counter for that particular team. If no-one has used it in a week, then the team would get an automatic +50% buff.
This wouldn’t be spammable … as soon as a rare team is used, it’s locked out for a week.