Ok, let me break it down a little
The SWM LNB is only capable of running 8 tuners. (each DVR even though only use 1 line equals 2 tuners). Now, you can switch a DVR to single tuner mode subtracting a tuner if need be.
So if you have 4 DVR's and 5 Standards, and don't want the hassle of running new lines from the dish and changing out the LNB, then switch one of your DVR's to single tuner mode.
If you want to run more then 8 tuners, you will need a SWM 16 or a SWM expander.
Both of these use the Legacy LNB (the 4 line one).
After that, DVR's will use one line and you can have MRV and all that good stuff.