Not child abuse but I work in injury claims so the same sort of principles apply. While this is a group action all the claims will be different in terms of effect and value. The length of the abuse is only relevant in how it affects the outcome.
Some people will have gone on to work normally but will still get damages for the psychological effect. Others not unreasonably will potentially have become recluses and not worked at all or never fulfilled their potential. They may have needed a lot of looking after. That leads to more damages. Some killed themselves tragically. That leaves bereft relatives who will also be entitled to claim.
I suspect at present thompsons main focus is in establishing liability. They need to establish that celtic owed these kids a duty of care. From a professional point of view I think they will succeed in that. Kids are vulnerable. The duty is higher. Once that's done they get busy on quantifying the claims.
It's not just the damages though. The costs of pursuing and defending it will be huge. I'd suspect that while it would be preferable for them to come up with standard values it wouldn't work that way.
Just remember thompsons and their lawyers will have big teams ploughing through loads of documents and statements at £100-£200 per hour.
Sorry I don't post much but I hope this is helpful. The long and short is this could prove massively expensive. Even more so because these kids were full of potential. On their way to being professional footballers. If they end up a basket case their potential earnings come in to play.
I'm happy to try to explain more. I'm not qualified in Scotland but I deal with some Scottish cases for medical malpractice. The principles are broadly similar.
As for non disclosure there would still be the admission damages were paid. And in most right thinking peoples book that means guilty.