Help Setting up Two Parallel WiFi Networks

IF you have Orbi system and 3 satellites, this system will be more than capable of handling 50 sevices. Placement and distance is key as well. If your getting bad performance from the system, then some troubleshooting is needed to find out why the Orbi system is operating badly. Adding another wifi system will only make things worse.

What Firmware version is currently loaded?
What is the Mfr and model# of the Internet Service Providers modem/ONT the NG router is connected too?
Is the Orbi system operating in Router or AP mode?

What is the size of your home? Sq Ft?
What is the distance between the router and satellite(s)? 30 feet or more is recommended in between RBR and RBS to begin with depending upon building materials when wirelessly connected.
https://kb.netgear.com/31029/Where-should-I-place-my-Orbi-satellite

What channels are you using? Auto? Try setting manual channel 1, 6 or 11 on 2.4Ghz and any unused channel on 5Ghz.
Any Wifi Neighbors near by? If so, how many?

Try enabling Beamforming and MIMO(MIMO may or may not be needed) and WMM. Under Advanced Tab/Advanced Settings/Wireless Settings

Also try turning down the power output of the RBRs wifi radios from 100% to 50% and see if this changes anything. Under Advanced Tab/Advanced Settings/Wireless Settings

Try disabling the following and see:
Armor, Circle, Daisy Chain, Fast Roaming, IPv6 and Set 20/40Mhz Coexistence to 40Mhz only. Set Short preamble instead of Long preamble modes. Save settings and reboot the router and satellite(s).

One User Experience/Configuration:
https://community.netgear.com/t5/Orbi/Most-Stable-Orbi-Configuration/m-p/1941087/highlight/true#M97026
https://community.netgear.com/t5/Orbi-AX/Community-FAQ-My-Orbi-speeds-are-slow-inconsistent-and-don-t-my/m-p/1982974/highlight/true#M7849

For any other non NG branded products, please refer to there help and support web page and community for information regarding there products.