From the fist page of the linked Vishay datasheet (In case it disappears in the future):
- No suffix = Single.
A = Common Anode.
C = Common Cathode.
S = Series connection.
BAT52 != BAT54 but I have not compared datasheets.
And you always have to be extremely careful with any part in a SOT-23 package. The trouble here is that manufacturers do not agree where pin number 1 is on this package. The numbering shown above is the most common, but you can’t rely on that.
I did a picture search, but could not quickly find one of the alternative pin numberings. Some of the datasheets do omit pin numbering at all and show pictures like in the Vishay datasheet, but without pin numbers.
But you can find texts like these:
You can put both diodes in parallel to push a bit more current through a SOT-23, but it’s a small package and limited by dissipation, so a diode in that package is never going to conduct much current for long. some MOSfets in SOT-23 do 3A or even 5A, but those have a very low Rds-on and therefore low dissipation.