First of all, due to my OCD I have added full club names for as many clubs as I could manage, with over 1000 teams in the country I didn't manage all. I completely understand many people will prefer to have 'real names' but perhaps not to the extent of which I prefer, but for me this adds to the realism of football manager, maybe some of you would share my OCD'ness.
Keeping as much to the real life structure, I have mainly tweaked the lower levels of Spanish football, adding regional leagues (Under Spanish Third division - Tercera). I have used as many real tournament names as I could, but I do understand they do not completely correspond to real life, but for my own fantasy game, this re-structure makes makes more sense, and enables me to be able to manage a regional team and work them up the pyramid.
I have literally regionalised every single team in spain, because I noticed that after the Tercera division, there were many teams missing lower regional leagues, and also looking at the country geographically, it didn't make sense to me that some clubs from certain regions could be promoted/relegated to a number of different regional divisions. This way I have grouped them based on where they are located on the map, to make the promotions/relegations as realistic as possible, to ensure that teams in the very north, would not be relegated into the southern most regional league.
I had noticed the following: You obviously have La liga (1), Segunda (2) - Then Primera division (3) which is 2 groups (divided east and west) - Then Segunda-B (4) with 5 groups pretty much divided North West, North East, Central, South East, South West (forgive me if I am a bit off here) - Then Tercera (5) with 18 groups, according to the 18 autonomous regions in the country. So what I have done is added each of these regions at lower level, where I have called them Preferente Primera and Preferente Segunda (as I noticed that at this level, many of the divisions are named 'preferente etc etc'.
So with my pyramid, you are now able to manage teams in the 5th level (Tercera) who get relegated into the regional divisions at 6th level, who get relegated to regional divisions at 7th level, with no further relegations. (If you are interested, you can even open the file in the Pre-Editor, and you will see that all teams in the 'Catalunya region' for example, will have corresponding regional divisions etc.
What I have also done, is add a number of C teams... I really like that in Spain you have B teams, and many clubs have/have previously had C teams, for example Las Palmas have their 1st team, a B and a C team, and I really wanted to bring back the likes of Barcelona and Real Madrid C. (These teams have been added to the lower regional divisions, which now means you can start out at Real Madrid C, and if you do well, perhaps you can get the job of Real Madrid Castilla (B) and later on the glory of Los Merengues themselves!
Furthermore, I have completely revamped the youth league system... bearing in mind, in real life this is absolutely gigantic!!! With many thanks to a website called lapreferente, which has all the regional/youth league results and tables and a heck of a lot of info on all these minnow clubs! LOVE IT! So I have used this to great extent to enable me to restructure the Spanish Youth League System... Despite not being able to manage at this level, I always find it nice to see your kids team competing in a proper league at their age.
There are 7 groups at top youth level, underneath this in the next step on the ladder, (if i am not mistaken) there are over 50 odd groups all based on regions... Now I didn't want to go that far, but I have added 4 levels under the top division, with the majority of leagues containing 18 teams, so basically now 7 leagues at 5 levels all have youth teams competing in proper tournament football. All of these leagues have been structured with promotions/relegations, the top league with a championship play-off (which is actual in real life) - There are a few things I just could not manage to achieve in the Basic Nation Rules, for instance, the amount of teams who qualify for the Junior Copa del rey, among other things, but I have given it a good go, and in my book, its pretty exciting.
Many clubs have their Under 19 (or youth team) and also B, C and more teams at youth level. I have myself played football at a decent youth level in Denmark, where some clubs had 8 or more teams at any one age group, so in this revamped youth structure of Spain, you will see the likes of Real Madrid, Barcelona etc, having their B and C clubs with an Under 19 team.
That is about all, I am sure I have lost many of you already, but hey, just wanted to give this a try, see if any of you fellow FM fanatics would be interested in giving it a go, I would be very interested in hearing your feedback, any potential changes or errors.
As I mentioned, this is just one of a number of databases I have edited, others include a restructure of the English system down to level 10, Danish and Swedish leagues, Ukrainian, Portuguese among others. Perhaps one day I can add them if anyone would be interested in giving them a try too.