Scottish Universities generally do 4 year degrees, which students in Scotland can get into with their Higher qualifications, which are roughly equivalent to AS levels. (Though in fact a lot of Scottish students will stay in in school for another year after that and do 'Higher Still' qualifications which are more like A2, and then do the 4 year degree)
They will sometimes allow students with good A levels to skip the first year and go straight into year 2.
I'd say there are a lot more downsides of going straight into second year - the staff will be assuming that you're already settled in, used to the system, know where to find things in the library or labs or whatever, and that you are already settled in with accomodation, friends, clubs, everything really!
If you start in year 1, you get to be part of a group of other new starters, get all the introductory tours, and everyone understands that you are new and confused!
Plus, the structure of most Scottish degrees starts much broader - details vary, but back in my day I really was admitted to the whole Science faculty, and had my choice of any of the subjects on offer (subject to timetable of course) so I could do a wider range of things in year 1, then specialise gradually over the course.
If he knows he wants to do law or medicine, that doesn't apply, as they are more focussed from the start, but if he is interested in 'science' or 'languages' or 'arts' it gives a chance to try out a wider range and get a feel for what suits him at that level of study.
The only downside is the money, which you say isn't an issue for you anyway. He might be older than average, but not by much - most 1st years are 18 or will be very soon, plus a lot now don't go straight from school anyway.
I don't think employers would even notice.