Multiple PPOE-client connection to serve many users

Hello all, We are an interneg service company.
Can anyone help.
If we have 2 routerboards.

Router 1 : for PPPOE customers
Router2 : For pppoe-clients connections

Lets say we have 10 active pppoe client connections serving as WAN
and we want to load share this huge bandwidth to the other board which is the users BOARD.
how can we achieve this please ?
Is there any way to merge the speed of all these pppoe-clients to get it all on the other board ?
i searched too much for this topic and could’t find much help in doing it .

Is the only way PCQ ? and if yes is it successful for 100-200 users ? can anyone provide detailed script to achieve it in the new ROS versios ?