It's entirely possible that even if the task force trying to reach Wake had arrived after the second attack began it could have entirely ruined the Japanese invasion force's day. Even without the task force, the Wake invaders on Wilkes wiped out the Japanese trying to get ashore there, and overall 700 of the 2000 total Japanese force were killed. Major Devereaux (sp?) only surrendered after he was told no relief was coming. What if he hadn't? Better yet, what if the American task force hadn't gone to Midway and instead come to Wake?
What task force are you talking about? It's generally better to start out with just one alternative by the way and detail it. These threads generate spin off alternatives at a tremendous rate anyway.