I had thought the same myself about taking all 3 although Bridges wants to play mostly 3. If Cal can sell him on the "positionless players" thing and plan on running his 4 out, 1 in offense, then the only thing separating the 3 and 4 are who they guard on defense.
There is definitely more than 1 recruit Cal is directing the "positionless player" talk to. Monk, Simmons, Bridges, and who knows who else?