Squad Sunderers are a little too powerful

whoops, ignore.

A post filled with generalizations of this quality its hard to no just ignore and throw it in the trash. Entirely simplistic and non constructive.
Listing how a large force spamming anti tank weapons make a good soft counter to sunders sometimes giving no specifics to the situation in the most vague terms isn't really addressing OPs concerns directly. You are just theorizing a minmaxed response to a vague perfect scenario and pretending there are no other factors anyways.

To respond directly to the OP

1. It does not remove the need for a beacon. Beacons are still highly useful, and synergise very well with an IFV Sundy. You can, however, no longer guarantee a sundy kill with a beacon placement and a few guys ready to drop, which I think is a positive influence on the game. Previously a deployed sunderer was impossible to efficiently hold vs a concerted attack.

2. Deploying it allows people outside of your group to spawn. Rotating squad lead through platoon while getting people to wait on the spawn menu is bordeline non-viable, purely given the amount of time it takes, and the amount it overrides voice coms. Yes you can theoretically spawn a platoon from a sundy, but are you going to rotate those guys again when they need a respawn after 1 death? If so your platoon lead is doing nothing else, your voice coms just became useless.

3. I addressed at length already. Same number of players and resources focused on killing a battlebus will do so, or are bad players.