my first thought is no.
why do you want Zobrist?
I don't think Weaver is going to be this
good, but he is still an ace. losing Weaver I think leaves your pitching not as good. Marcum, Hanson, Wandy, Kuroda, Wilson, Floyd, McClellan.
I'm not a fan of McClellan. as the season goes on I think he is going to hit a wall. he has been a reliever in recent seasons. IMO Wandy should only be used at home. he has had great seasons at home during his career, but not so much on the road.
getting Bell is OK. closers come and go so much you could
maybe get additional closers off waivers, but Bell IS someone you can count on.
I don't think your team needs Zobrist. I'd rather have someone other than Zobrist with Bell, but that's me.