Canadian P.J. Perry may be a lesser known altoist, but he's a fine player.
Also, strikes me that even the best-known jazz musicians enjoy a nice payday as a side-person.
Another. Top rate jazz players often had club dates in Toronto, thereby giving Canadian musicians the chance to record with them during the day. Again, a nice pay-day.
With Jimmy Cobb in mind
Lesser known does not mean lesser quality. All these are fine recordings.