I, and a lot of others, have a D500 that has a third LNB input on the main LNB, and you daisy-chain the 129 or 61.5 wing dish's feed into that. You can use a D300 or a D500 with a single DPP LNB for a wing dish. Or if your locals are on 129, and you have full LOS, just use a 1000.2 dish/LNB that spots all three birds.
No multiswitch needed in either case; just a separator (not splitter) on the back of the 622.