More means better, but not much better because of crit diminishing odds lol. From the developer post, 20 crit is near 20% crit chance and 100 crit is near 66% crit chance, so it starts as a solid 1-1 % value, and the chance/crit decreases the higher the value of the stat. So taking an estimated guess:
1: Shonne with only 45 crit mod: 10 (crit base value, all toons have) + 45 = 55 total crit, Near 45~50% chance by diminishing odds maybe (still on the low end of crit %, so it isnt reduced very much).
2: Shonne with 45 crit mod and 35 crit wpn: 10 (base value) + 45 (mod) + 35(wpn) = 90 crit, from what the devs said, this should be near 60% chance maybe
So you will get only 10~15% crit chance from your 35 crit weapon if your mod have a high rool already. Then maybe a 40% atk on slot 1 is more benefitial, as weapon atk/def % is multiplied by lead %, leading to higher values than the flat base 40%.
If your aim is to always disarm tho, 10~15% extra chance will be benefitial, even being low. Personally i would prefer the huge increase in ATK. but all choices are cool.