30 years ago I was on a 3 week residential course for work down south and there was a little ginger haired fella - only early-mid 20s - and he fitted your description perfectly. About 5'4" and 7 stone wringing wet, but oh, the guys he'd knocked out! And he was pretty much a millionaire already of course, but was nevertheless going to be the top earner in the company within 2 years. Could drink anyone there underneath the table of their choice. Had a different lass every night too - what a guy!
Of course, entirely predictably, come the last night everyone's hitting the bar and there he was, little Billy 2 pints. By 10 o'clock, he's off his face and sobbing his eyes out that he constantly felt like a failure and how all the ridiculous bragging was all just a front after all. I was shocked, I tells ya...