Few are. Most aren't.
You might find value ocasionally if they allowed 2 teamers. Any value with 3 teamers I would say is extremely rare, but I'm sure they pop up. Too much time involved. But if you have time, and lots of it, one might come out on top.
Stick with betting all 3 seperate. 2 of 3 gives you an up day. Keep getting 2 of 3 with sportselect and you are dogmeat.