Non Compete clauses are notoriously difficult to enforce, there is an element of not stopping someone from healthy competition to be taken into account. Therefore non-compete clauses are often ignored even if in contracts and taking someone to court for breach of non-compete is extremely expensive and time-consuming. Depending on the individual case there is no definite chance of winning so it rarely happens. In your case it's unlikely one technician leaving a salon to set up on their own would have such a detrimental effect on the salon that they could provide significant evidence of.
I've done some Googling (taking into account you are in Scotland so laws are different) and I found this which might help you understand where you stand:-
http://www.lawscot.org.uk/members/l...ates-2016/september-2016/non-compete-clauses/