Yeah he should use the smallest splitters possible. It looks to me like you have a lot or runs to several rooms maybe he had the wrong cable even. Did he check and trace the cables. He could have even trying to use the cable for the 2nd lnb line in the old system instead of the first. Also make sure he connects the power supply to the right leg of the splitter if he's putting it after the splitter.
He was using the original cable that was working before installing the SWM16. He ran an additional cable from the SWM16 to a second splitter which was going to be used for the Genie. Since he could never get a signal to my HR24, he never tried hooking up the Genie. The power supply is right before my HR24 and is working fine with just the single splitter and original LNB.
I don't really know which leg of the splitter it is connected.