[UNET] Two server architecture, Is it viable with HLAPI or should I go with LLAPI?

I am building a game where a player controls only a battlestation of a ship (ex: one is piloting, another is shooting etc.)
It is also meant to be 3v3 game where 2 ships dodge fight.
The players use mobile phones as controllers and ship surroundings is shown on a big display.

I started building а prototype using HLAPI but realized that I will need to do a lot of manual sync work between the “two” servers. I do not think I can send the same information to two hosts from a client so I will need to sync manually all SyncVars and Cmds between the two.

Is there anyway to do this type of architecture elegantly with HLAPI?

I have gone to LLAPI and using MessageBase for serializations.

I still think it is interesting problem and the question is interesting.