Easy the Brewers had a career year last year in total number of stolen bases with a 84.78% success rate. This year they are at 73.91%. You could argue the Brewers didn't try to steal enough last year. You want to stay around the 75-80%. So the Brewers should have tried to steal a few more bases last year.
Base running in 2024 they were at 19.7 and this year 13.6 so not really all that far off.
Stolen bases is also completely random as it depends on getting a good jump and running on the correct pitch and catching a team napping. A lot of times the runner is safe because the catcher made a poor throw or was just off a little bit. You are talking about milliseconds if a runner is safe or out. The 1st base coach or 3rd base coach are not going to impact it all that much.
If the 1st base coach had an impact you would see it year over year but I don't believe this to be true at all. Comparing one year to the next is just not all that significant and doesn't really tell us all that much.