Which gateway PC should set routerOS or layer3 Switch

RouterOS General
1

Hello,
There are about 10 vlans, they cannot communicate each other , but can go to internet and ONE DATA VLAN .
I now set routerOS as gateway, the firewall can be achieved only 2-3 rules.
However if I use layer3 switch as gateway , it become more complicate to set firewall rules.
routeros_gateway.png

2

My take would be to try to maximize traffic between the cisco switch ports and use the MT router only when necessary aka for internet traffic.