No need to apologise, I was more concerned with you wasting your own time waiting around for a reply that hasn't arrived. Start off by thinking why the SuperHub (3 or 4?) isn't good enough for you. What's missing that you require? What features are must-have? Do you want an all-in-one device or are you willing to spend more for separated specialities, and potentially better stability and performance?
For example, a consumer all-in-one 'router' is actually providing the functionality of a router, switch, firewall, SNAT/DNAT, DNS server, DHCP server, wireless access point, and so on. You could theoretically split all those into separate boxes, but that's rather wasteful.

Depending on your requirements though, it could be useful to have a dedicated DHCP server, or DNS server, or to separate the router from the hardware firewall. Certainly splitting off WiFi to a dedicated AP is to be preferred.
Do you see what I mean? "I need a new router" isn't a straight forward question with a standard answer. If your answer is along the lines of 'My requirements are to connect a few devices to the Internet through my VM modem', then any old device capable of gigabit will do you fine, more or less. So then we're back to asking what's actually wrong with the SuperHub as it is without the third party add on box?
If, on the other hand, you were to say something like 'I need a gigabit WAN router which has three or more separate interfaces for segmented networks and that can handle IPSEC and WireGuard at wirespeed, a stateful firewall with complicated DNAT rules, a bulletproof DHCP server for 250+ users, DNS with filtering per-client and with content blocking, a layer 3 switch with VLAN support and PoE AF, and a WiFi AP solution with remote management and backplane to cope with multi-100s of users with seamless roaming'... Well then we need to have a different conversation...
If it's as simple as finding the VM router 'a bit flaky' and wanting 'better WiFi' then pretty much any decent router and a stand-alone wireless access point located centrally in your home will do you fine. If it's more than that, list your requirements more specifically than you did in the OP and we'll hopefully point you in the right direction.
Edit: At any rate, avoid anything by Asus as a matter of course. Netgear aren't much better. If it must be an all-in-one type affair then something that supports WRT or similar will be your best bet. Better yet, get something more focused with a better security track record, or even build one.