Line Counter Reel issues??

So we checked the accuracy of our 4 line counters in which 3 are strung with 20-8 stealth braid and 1 with mono. We found some inconsitiencies between all of the reels. These reels don’t have backing mono on them does that make a difference as far as accuracy of the linecounter?? I know 2 of them have exactly the same line because they were brand new spools. What do you do to insure the linecounters are as close as possible when restringing?? Thanks