For the 2022 Season, I've added a small new feature to the Batter Cards:
For "aggressive" base stealers, the word 'Steal' is shown in red on their card (the mnemonic I'm using is "red = reckless").
For "selective" base stealers, the word 'Steal' is shown in purple on their card (the mnemonic I'm using is "purple = prudent").
To decide if a player will attempt to establish a lead:
1) Start with the baserunner's Speed.
2) If 'Steal' is shown in red, add 1 to this number.
3) If 'Steal' is shown in purple, subtract 1.
4) If this is equal to or greater than the catcher's Arm rating, roll to establish a lead.
I'm still working on some tweaks to the above rules based on the in-game situation (and trying to keep them simpler than the Auto Manager rules in the rulebook). Until then, these should serve you fairly well in terms of reproducing each player's season.