Quick update to this topic from one who knows!!!!
DUM started season 18 with -
age 0 - SL 5, SL 5, SL 10, SL 10
age 1 - SL 10, SL 10, SL 10, SL 20
age 2 - SL 10, SL 15, SL 15, SL 20
age 3 - SL 10, SL 10, SL 15, SL 20
age 4 - SL 10, SL 15
age 5 - SL 10, SL 20
Perhaps I could have done better than last place in the league - probably, but not much better.
For what it's worth, I would recommend some changes to the above for anyone else who tries the expansion route.
Firstly there are no players over SL20 although at least one of the previous options has at least one player at SL25.
Secondly there are too many crap players who don't even feature as 'squad' players.
To overcome these two problems, I would suggest that at least 2, but more likely 4, SL 10 players be scrapped and their SL should be spread to others. I would scrap one SL 10 guy at ages 1, 2, 3 and 5 or ages 2, 3, 4 and 5. That gives you 40 SL to spread around.
How about this...
age 0 - SL 5, SL 5, SL 10, SL 10
age 1 - SL 10, SL 15, SL 15, SL 20
age 2 - SL 15, SL 15, SL 25
age 3 - SL 15, SL 15, SL 20
age 4 - SL 25
age 5 - SL 20
That's only 16 players, but with a Bosman, you're up to 17 and two of them are SL 25. It's not brilliant, but it's better than no players higher than SL 20.
It won't affect me again, unless I'm asked to take over some piss poor team in the future, but it might help you