I looked at ownership rates for pairs of players, using the
data dump. Main finding is that stacking isn't that common; there isn't that strong a tendency for NFL teammates to be on the same team.
The most common pairing, on 12.6% of rosters, is Rashee Rice + Taysom Hill. Rice and Hill are the two most highly owned players - 37.2% for Rice and 28.4% for Hill. By chance you'd expect 10.6% of teams to have both, so 12.6% is just about +2% higher than expected (+2.1%, given rounding). Turns out that the 10 most common pairings all involve Rice, the most owned player.
The pair that is on the most rosters over expected, at +2.7% over expected, is Caleb Williams + Rome Odunze, who are together on 6.4% of rosters vs. 3.7% expected (23.0% of teams have Odunze and 16.3% have Williams). At 6.4%, this is also the most common pairing of teammates.
But most of the top 10 most common pairings over expected are just pairs of commonly owned players. CHI Williams+Odunze in 1st at +2.7% and WAS Daniels+McLaurin in 10th at +1.7% are the only two that are teammates. 6 of the top 10 involve Rashee Rice (including the Rashee+Taysom pairing already mentioned) and two involve $3 PK Joshua Karthy with $3 PK Bates and with $3 DEF GB. So the pattern of "a team that drafts some of the obvious highly-owned players also drafts others" looks stronger than the pattern of drafting teammates, and the pattern of some teams going for the cheap kickers & defenses is about as strong as the pattern of drafting teammates.
Another way to look at the CHI Williams+Odunze pairing is is that Caleb Williams is on 28.0% of teams that have Odunze vs. 12.8% of teams that don't have Odunze, a +15.2% gap. Ignoring some rarely owned pairs (who are together on <1% of teams), and focusing on the relative ownership rate of the less owned player, this is the 3rd largest gap. The largest 5 are:
+17.2%: Brandon Aubrey on 25.7% of teams with SF D vs. 8.5% of teams without
+16.1%: Cairo Santos on 22.8% of teams with CHI D vs. 6.7% of teams without
+15.2%: Caleb Williams on 28.0% of teams with Rome Odunze vs. 12.8% of teams without
+14.0%: Ravens D on 21.2% of teams with Justin Tucker vs. 7.1% of teams without
+13.8%: Christian McCaffrey on 19.2% of teams with CeeDee Lamb vs. 5.3% of teams without
That's two kicker-defense team stacks (CHI & BAL), one case where people who take the most expensive D also take the most expensive PK, and one case where people who take the most expensive WR also take the most expensive RB. Just two more stacks with a QB make the top 20, QB Levis at +12.0% higher on Calvin Ridley teams and Terry McLaurin at +11.2% higher on QB Daniels teams.
I would've looked more directly at how common stacks are, but the data files don't include which NFL team each player is on and I didn't want to go through the schlep of trying to add that, so instead I just looked at the most common pairings (calculating that a few different ways) and seeing what the patterns were.