Congratulations on the success so far. I grew up not so far from Tullibody and I'm currently managing their biggest local team Alloa in my save, so have been following with some interest.
I don't think I could ever bring myself to hire a HOYD with unambitious personality! Having said that, the ones I do hire with good personalities don't seem to make the slightest difference in my youth intake personalities, so you might be right. Despite being pretty youth focused myself, my WWY attribute was fairly low too, but when I started praising the Under 18's training performance a bit more it seemed to lift it up.