I was looking for info about if I can use two Orbi RBS350 satellites to an Orbi RBR750 router

Ok, so if I understand you correctly, I can as I thought use these together but the satellites will be limited to their own maximum capacity and the router will be limited to its own maximum capacity, right? For example, the devices that are connected to the satellites get the maximum capacity for the RBS350 and the devices that are connected to the router will get the RBR750 maximum capacity? Am I thinking right here?

The thing is that I at this moment have an RBR353 system but got an RBR750 router from a friend, he needed to buy an extra satellite and at that time it was cheaper to buy a package with one router and one satellite.

I don't fully understand this with the update, can it create problems if I update the RBR750 router or if it's all ready have the latest firmware? Don't know if it has any significance but I don't know the firmware version of the router but I think it has the latest version doe it is produced in 2023 and the RBS350 has firmware version V4.4.1.29.

Does it matter that the router has tri-band and the satellites have duo..? I mean the communication should work anyway since the router has the higher standard of those two, right?