What rule to apply according to the scheme?

Question

Mikrotik

There are three networks. 1 terminal server. To relieve the load, we organized such a scheme with three terminal servers. . Yes, not to redo the rdp connection for everyone and not to apply group policies.

Answer 1

and on what exactly this or that terminal server should be selected?

Answer 2

Why didn't they leave one?
Register static routes to the terminal from all networks, and let everyone go to one.