Yessir, perhaps unless Chris Paul or Griffin bust a knee in the near future. Good talent gonna be sitting there, and Jeff Green could be a long-term Pierce replacement, at half the money.
Even then though, Westbrook on this team would make the C's contenders. This offense doesn't need Rondo's excellent playmaking as much as it does a lights out shooter to make this offense first rate, as long as that shooter can also drive to the hoop like Rondo can, which Westbrook can.