If you want to control the game, get one or two of the Big Balls, Hang High, and then decide if you need to score them for both you or the opposing alliance (Stationary goals). You can then easily add points to the opposition. (You also might be able to uncap the oppositions stationary goal.)

This was the winning strategy in 2000 by team 255. Get the balls, Hang on the Bar, and then score them.

Is this mechanically feasible - I don't know. A team that does this needs to rely on its partner to score the small balls. A perfect robot would be able to hang, score big balls, herd little balls - and this is pretty challenging.
Just buildng a robot that can climb the big steps and hang is a challenge.

A smart development plan would be to design by objective:

1. Build moving platform cable of herding, releasing
2. Add Arm for big ball manipulation
3. Add stair climber
4. Add hang ability

6 weeks, 5, 4, 3, 2, 1 ship.......