I take it having multiple good candidates increases the odds of that, and then a runoff increases the odds for one of them prevailing over Moore?
The question is how many of those candidates have both the resources and the visibility. Stopping the RINO Establishment preferences (namely Rep. Bradley Byrne) is paramount. Moore still remains the anti-corruption, anti-Establishment leader, given the lengths to which the RINO Machine went to stop him from being elected. Sadly, Trump grievously erred in 2017 endorsing the corrupt appointee Luther Strange, who got the job as a payoff for not indicting the corrupt ex-Governor who appointed him.
This is one instance where the President and his surrogates are better off not making an endorsement (or attacking Judge Moore), because if Moore does get the nomination again, the media will use that to attack Trump. Let the primary voters in AL sort this one out and make the best decision.