>>392771091
I would seriously recommend 3, since I have 2, and you need the 2 to be extremely stable to keep tracking acceptable. A third would help a lot with correcting aberrations, and I don't even use trackers.

If you cannot do 3 without seriously going out of your way, then make sure the 2 you are using are extremely stable. Otherwise, just dish out the $100 or whatever for a third