I'm under the impression that it is far less likely to contract AIDS/HIV when you swallow than when you bareback
correct me if I'm wrong

Well if you base it solely on statistics, it is far less likely, actually less than 1% chance of contracting AIDS/HIV during oral sex in general even if you swallow. For AIDS/HIV to take effect in your body it has to go into the bloodstream, meaning any break in your skin will most likely allow entry of the virus. During oral sex, unless you have open sores in your mouth or a wound in your gums/oral mucosa, then the danger of contracting the virus is really quite low.

Anal sex in general is very risky especially if unprotected for the bottom/receiver. The anal mucosa is quite sensitive to friction so penetration of the penis usually causes breaks in the skin of the anal entry, thus allowing the virus from the cum to penetrate. Which is why we really do advocate penetration with protection! Hahaha hope this kinda helps