Why would a guest get up for some rude jerk who tries to kick them out of a seat.
When I come to a shul, if I want to sit, I sit. If someone comes and tells me it’s her seat, I motion to be quiet because we’re davening.
If they start davening on top of me, I pull out a can of sardines from my talis bag, and open it near them, taking care to spill the oil. This method has a 98% success rate.