Depends on the Axis team
You can change the objective count as a server admin. Just open up the pk3 of the map, go into maps/obj and open xxx.scr in notepad.
Change the line that states level.targets_to_destroy 1 (or something like that). You can set it to 2 (recomended) or 3.
Personally, I think 3 is too much and you're entering the realsm of making the job too easy on a solid and organised defence.
2 should be ok, though.