Lane Spaces

[Triad zebra]

*8.1.4 SITUATION: A1 is at the free-throw line for the first attempt of a bonus
situation. In (a), two Team B and two Team A players occupy the first and second marked lane spaces, respectively. B3 occupies one of the third marked lane
spaces. A3 attempts to occupy the vacant third marked lane space.
RULING: Illegal in (a), A3 is not permitted to occupy the third marked lane space. Only two offensive players may occupy marked lane spaces during a free throw.

Wouldn't this play be clearer if instead of A3 it said A4? One of the veterans is claiming that the Two Team A Players are A2 and A3 and therefore no team A players can have the 3rd spot closest the shooter. I told him he needs to assume the two team A players are A2 and A4 and A3 came in as the 3rd offensive player. Correct?