ridiculous

Another hard one.

I liked the metals group - but I think you mean Tina Fey.

Hidden tools - Bowie is a type of knife, and there is no link between the others. I think if you're going to hide them, the relationship needs to be more obvious - all garden implements would work: fork, spade, hoe, rake?

Hidden Avengers - Ant McPartlin just doesn't work. Finding 'Man' in that is way too hard. There is a film director Antony Mann, who might work better.

I liked the 'Bob' group.

I think this is a good grid - with a couple of tweaks. IMHO. :-D