problems about VPN connection over multi-ISP

I have two Mikrotik routers, router A has two WAN interfaces (ISP NAT network), router B has a WAN interface (public IP), and router B is set up with an L2TP server. I want to create two clients to connect to the two WAN interfaces of Route A, and then superimpose broadband through EoIP. I currently don’t know how to create two VPN clients to cennect the different WAN interfaces, or someone tells me, is my idea feasible?

It is possible to set up two L2TP clients on the same router to connect to the same remote server, each via another WAN. Soing so involves use of the src-address parameter of the /interface l2tp-client row, and use of policy routing that takes source address into account when choosing a route. But you may have unrealistic expectations regarding the aggregation of the two tunnels - assuming you’ve got the two L2TP tunnels working, what exactly do you plan to do with EoIP?