Initially thief have 35 sec recharge rate
With all trickery line 27 sec
With “Sleight of hand” trait 21.5 sec
In manual calculation obtained other numbers
35 – (3.5×3) = 24.5 all trickery line
where (3.5×3) 30%
24.5 – (2.45×2) ~ 19.5 “Sleight of hand” trait
where (2.45×2) 20%
or
35 – (3.5×5) = 17.5 all trickery line + “Sleight of hand” trait
where (3.5×5) 30%+20%
Your system of counting time seems to be wrong
Please, check this or explain the difference in time