I'm in a number of bands (P/M in one) and the three band chanters I use are as follows:
1-Dunbar poly with Soutar reed (plays at A=448)
2-McLellan poly with Apps reed (plays at A=460)
3-MacHarg with Gilmour reed (Plays at A=474)

Each of these chanters in addition to the obvious point of being not-in-tune with one another have verious colorings for the notes. The timbre that each has is distinct and unique. Each blends perfectly with its' fellows in the respective bands, but, obviously, would not play in tune with one another.

In the "jamming" circumstance put forward in the original question, the experience can be great or jarring-it depends.