4-6 tuner signal quality degraded due to splitting?

I have one TiVo Premiere and two TWC MoCA DVRs each with two tuners. Therefore my cable is split between the 3 boxes as well as my modem. Once in a while I get pixelation on a channel and my cable company will say it is because my cable is split three ways so the signal strength is reduced for each box. If I make the jump to a 6 tuner TiVo Roamio Plus/Pro, does the fact that I am going from a 2 tuner TiVo mean my signal quality will be further degraded (threefold?) or does it not work that way and the signal strength will be just as high as the 2 tuner TiVo? Thanks