Here's the tactic.
This was started as Bielsa's Leeds recreation save (I've only changed sides bcs of my players' footedness), so the roles were chosen having that in mind. As I said, I'm sitting top of the table with Derby right before the winter break of the 2022/23 season (no transfers / loans were done, the squad is the "default" Derby one ).
Regardless of league position, I'd say my tactic is clashing with the following general principles explained in this thread:
1) Width
I'd say the fullback/winger roles are not the best as both flanks lack width, even though both AMR & AML, as well as FB(su) have "stay wider" PIs. I tried plying the left back as a CWB(su), since Ayling is both footed and often roamed and drifted inside. But I gave up quickly as the CWB role was to aggressive to allow the player to participate in the build up, which was a big aspect of Ayling's game under Bielsa, so I decided to go with a simple FB(su) and a creative defender (pretty much a BPD profile player) there.
2) Disjoint midfield
As for the midfield trio, there is a defensive duty DM and two roaming roles in CM slots. I believe that, more often than not, Kalvin Phillips played as a Regista under Bielsa. Phillips was always roaming around (especially during the build up) to make himself available to his teammates, and then often playing direct long balls forward to switch the side/momentum of play. This is why originally I went for a Regista here. But I suppose having the entire midfield roaming was not the best decision ever so I went for a simple DM(de) with "more direct passing" PI. I haven't been experiencing any issues of disjoint play - maybe bcs of relatively high mentality pushing the DM forward? The RPM has the "Comes deep to get the ball" PPM, so maybe this helps a bit too?
Instead of the Mez(at), I've used a Mez(su) originally, since the support duty role also has the "get further forward" PI hardcode, which is reinforced with my "Underlap right" TI. But what I've found watching the games and statistics was actually that the attack duty is more productive - not entirely sure why?