If it's the Guards you want to join go ahead and tell them at thge careers office. Remember that all the posters on ARRSE were once in your position and look at how they've turned out. No don't do that it'll put you off completely. Seriously go for it and enjoy it which you can if you put your mind to it and be aware that it won't be all roses.
My first posting out of training from Bordon was a few months with the Grenadier Guards in Munster and then with the Coldstream Guards who took over from the Grens. At times I regretted being posted to 2CG so early in my career. After 2 CG, I found difficulty in settling down in subsequent units ,always comparing them to the Coldstreams, and marking them short, very short.
An excellant unit.
RSM Walsh 2CG looked around 5'6 to me. But speaking of butt. When 2CG took over the North Howard Street make shift barracks in '70, most of the toilet bowls were junior. Really TS for a 6'+guardsman. One of our REME fitters was 5'5", some wag made a ladder for him to reach his bed. (not a bunk bed)
I remembered this towering giant of a Sgt Major, Bunny Whitehead, I think his name was. The height from the ground to his waist must have been 5'8", because when he stood in front of you all you could see was his belt head.
There was a MG's parade , and the LAD not accustomed to seeing the Guards at thier best, were taking in the view while formed up on parade. Out steps Bunny Whitehead, stood in front of the LAD and bellowed, "DON'T LOOK AT ME, I DON'T TELL YOU HOW TO USE YOUR F*#&ING SPANNERS."