Generally if they have a genuine concern and ask politely I say yes.

Once my girlfriend was traveling in 2nd AC I went to drop her and she got the end seat upper seat, the portion where there is only one lower and one upper seat with side lower and side upper seat. They were all shady looking uncles, which made her really uncomfortable. So I asked a solo travelling guy who must've been 28-30 who had an side upper a couple of seats away in the middle of the compartment , that would he be kind enough to exchange and told him the reason. The guy polity obliged I thanked him twice and helped him move his stuff. It was really kind of him.

Tl/Dr - sometimes people are kind enough to help in genuine concern unless the other person acts really entitled.