The simplest and most versatile way to do this is to have a dual polarity LNB, with each polarity via a splitter to one 2 x 1 or (4 X 1 Switch on the master STB. (Either, but not both.) You don't have to use all the inputs). One of these is controlled by the STB tone burst (A,B,C, or D control in the antennae setup of the STBs..
Using this you can have both working at the same time, either H or V.
There are many variations that could be used, but I think that this would be the best for your application.
Kindest Regards, " The Druid ".
Not quite what I had in mind, but should give the general idea. Just substitute the H and V outputs of the dual LNB for the C and Ku band inputs.