A coupe of stellar casino sets that are mixed-mold immediately come to mind:
President Casino on the Admiral (all are THC mold except for the $1 RHC chips, both primary and secondary) Casino Aztar Caruthersville (all are THC mold except for the $5 RHC chips with giant inlay, both primary and secondary set)
And several TCR recent releases contained oversize chips that were IHC while the rest of the set was RHC: Casino Aztar Evansville (primary and secondary), Par-A-Dice Casino, etc.
I'm sure there are many others; it's not uncommon for casinos to mix molds, or even chip manufacturers.
THC+RHC as a combo work just fine in my eye. I have PCA's with the RHC $1 chips and the Paulson Suits mold as $0.25 with THC as the $5. It doesn't bother me and none of my players have ever mentioned it.