Basically, I believe that the engine have a limited margin, so, it keeps the main essence and when a player has potential, has potential, and when he hasn't, he hasn't...
Like we expereinced with the SAs ... 5 players with FK SA never were a guarantee that we would have a perfect player for free kicks...
The last features basically ordenated and created a visualization about something that was internal and that I always mentioned, one is the weather, that created ordenated the scenarios, so in the old versions a game scenario had different factors impacting in each match and now, these seems to be linked to the weather so each option has a list of determinant scenario factors linked to it.
Then the Playstyles are the visualization/externalization of the internal role that the engine assigns to the player when you sign it, and these roles are linked to animations.
Previously you had to test the players to know if an attacking player was a scorer, or assistant, for example, or if a DL had options to be elegible to join the attack and score/assist time to time. These hidden factors are now visible.
Regarding margins and parameters, as I commented, I believe that its so complicated, because the game have a rythm, we play 28 days... the market, has 5* players in the main market...so, in reality, we already had the player positions, first of all to place players in the lines, then the roles were internally assigned and now we can see them by checking the playstyle, so this doesnt change or brings something new... in reality, what brings something new are the team bonuses+player bonuses and playstyle levels... this IMO doesnt change a lot the previous situation because these bonuses where adapted to the own beatability margin and the own limits that the engine have, so, I mean, a PS can never fix the score vs a +10% team... like, if we train fully the PS the player will gain 300%+ shooting... the margins need air and in the end, and the potential of any player is set as always, it is internally regulated by default when you sign a player. Here is decided if a ST will be able to score a hattrick vs a same avq opponent.
Then the team and player bonuses, more than a addition, it is like a layer added to the beatability margin... it doesnt start as an addition, the 0% bonus, gives a negative % to your chances... so, if 2 teams, 120% vs 125% meet, and the first has 0% bonuses and the second full 10%, the first team will look deactivated because the original margin (that decides the scenairio chances) which was initially a 5% differential margin, is converted in something like a -15% for the local because of the 0% bonuses and the local have... a +15 extra added to the starting margin, so its like a final +30% differance... or so...
lets say that 0% = -10% margin, 2%= -5% 4% = +0% 6% = +5% 8%=+10% and 10%bonus is +15% of margin added to the original onem the beatability margin as we know it....and somehow you can have perception of this if you dont train the team... there is a gap between both teams if one has bonuses and the other does not.