Phono stage with 3 inputs

Thoress Phono Enhancer has 6 inputs.

Or, you could by three Lino C 2.0 for $2500 each. "Stupid -Great for the money," Michael Fremer. 

Brinkmann Edison, 3 inputs, 2 inputs are XLR or RCA, 1 input is RCA only

Musical Fidelity M6 Vinyl and Nu Vista both have 3 inputs, I believe.

I use a Mcintosh C2500 which two phono imputs, MM & MC.  My 3rd TT uses a Jolida JD-9 into the AUX channel of the Mc.  This configuration was not overly pricy and performs well.  I also have a SUT in case I want to run three MC devices.  Tube rolling has gotten expensive lately so I roll cartridges, "Big Smile"