You don't mention how long you had each pair of kegs in each fridge but maybe the pils and bitter are just warmer than the other 2? The sanyo isn't cooling as much as the fridge? What your beer temp after pouring for each keg?
Maybe a tower cooler (blower set-up) would help too?
Next: isolate trials
Fermenting: IPA, Tripel, Egregious-ish, Barrel Fermented Dreg Lambic, Brett Trois Helles
Drinking: Sterling IPA, Carrot Blossom Cedar Aged Mead, RIS, Jalapeno RIS, Dusseldorf Altbier v5, Dopplebock v2, Cider, Rye Berliner Weisse, Sauerkraut Fermented Gose, Lambic, "Brett" Trois IPA, Brett Blonde, Kriek, Saison, Sour Blonde, RIS
Barrel aged: RIS, Rye Barleywine, Tripel, Wee-Heavy