Two Asus RT-N18U and RT-N12E routers via a switch. Media server and WiFi. How can they complement each other?

Question

Computer networks

At the moment, there is an Asus RT-N18U router with a configured wi-fi media server with two TVs.
One TV shows films of any quality without freezing, in another room a newer TV freezes, and very seriously.
There is a shield into which the wire from the provider is brought out, there is a switch, from it comes a twisted pair in the wall into two rooms. Where there is a PC and where there is a newer TV that freezes while watching movies via wi-fi from the media server on the Asus RT-N18U router.

The task is to connect a second Asus RT-N12E router via a switch and connect directly to the TV via lan, but at the same time combine the Wi-fi network into one and keep the existing media server.
Why exactly like this:
If the whole problem is Wi-fi passability in the apartment and / or a bad Wi-fi adapter in the new TV, then a direct connection to the Internet through the new router will speed up data transfer and there will be no more freezes.
I read the guides "Setting the bridge mode on the Asus router" and "Setting the Asus router as a repeater" everything seems to be clear there, that the repeater option in my case will not help me. connection quality will not improve significantly.
It turns out my option is a setting in WDS bridge mode? Will this mode allow the TV to use the media server?
I also want to improve the quality of the Wi-fi signal throughout the apartment. it is clearly low, even though the Asus RT-N18U router is considered powerful.
I have to decide if buying an Asus RT-N12E will solve my problem.

Answer 1

Since it is not possible to swap the switch and routers - buy another miniature router, and put it in front of the switch / instead of the switch.
there are no other options, or as already written - a switch with a VLAN, which costs more than redoing all the wiring.