We need a psuedo-primary, While scores of candidates isn't ideal, one or two would be worse because Davis would be able to use his proven-successful strategy (aka puke politics) of demonizing his opponent. With multiple opponents, he'll have more difficulty focusing only on the frontrunner. Also, more voters will find a candidate they really like, so that more voters would vote to recall Davis.
Not all of those who declared their candidacy will actually run, if they decide they don't have a chance. We'll see next week. After a few public opinion polls, the rest of the undecided public will choose between the few candidates with a real chance, and some more candidates might drop out of the race along the way.
Any more than one GOP candidate will guarantee a Democrat victory of the recall. Democrats will run a candidate in case their polls show Davis will be recalled. California already leans Democrat, by roughly 10%. Two GOP candidates versus one Democrat will split the already disadvantaged GOP vote. It's true that those who turnout on Oct. 7 will skew Republican, since they have the highest motivation to show up. Even still, Democrats will win if Republicans split their vote between even 2 candidates. Your point that Davis won't be able to demonize is well-taken but remember that Davis has chump change left in his bank account to use to demonize anyone. Even Democrats like Attorney General Lockyer are telling Grey to drop the attack-dog style or risk losing Democrat votes. We can handle Grey. We cannot handle hard-headed Republican politicians who think more about their glory than the good of the whole Republican party: some of these GOP candidates need to drop out, soon.