or, if your goal is to drive two 4ohm cabs with 2 amps, you can also just use an ABY box. There are many makers. Bass into the ABY pedal, out A to the TH500+Cab, one out B to the WA+Cab.
Hard to predict the real results until you try it. Could have phase issues, could have some comb filtering, or it could sound great.
give it a try, nothing to lose really other than the cost of an ABY box ($40-60ish new, much less used).
LIFE is good - remind yourself of that every day
MIA Deluxe Jazz
Turner Ren 4 fretless
Fender Studio Bass