One way to make the 4H shamrock easily would be to do it out of yo-yos.
And yes, boys/men are often very good at such things. Two of my guys have done quite well with costuming, one moving on to now making and designing steam punk leather items - top hats, goggles, etc.
If the interest is there, encourage it and they will do well. Interest overcomes many learning disabilities! Lack of interest means doomed from the start whether there are learning issues or not.
Let them have fun with it!