Your choice
I am not an expert here but you got no replies so here's my two cents.
I had a similar situation, the original 6A kit had one set of Clevelands. The purchaser of the kit ordered copilot brakes and got Matcos.
I tried to buy a second set of Clevelands (10-30???) but they were either unavailable or priced like gold bars. Couldn't find any on the used market. My past experience with Clevelands on a certified rebuild of the hydraulics was a nightmare, but probably partially due to not having done it before. It seems like the O-rings were non standard or real expensive and had to be gotten from Cleveland.
So I sold both sets and bought a set of Groves, with the intention of adding a second Groves later.
Groves were more expensive than Matco but IMHO were better made. Van's has a habit of using the *most inexpensive* option when putting together the kit.
Most builders opt to or have to install external springs on the Matco cylinders so they work reliably. Groves springs are stainless and internal. Groves, IIRC have a little more braking pressure.
In answer to your question, can you mix and match? Probably. Each set will function independently and shouldn't affect the other set.
Dave A.