How is Vigil meant to calculated?

The Perk: You and your allies within 8 metres of range recover from Exhausted, Haemorrhage, Mangled, Hindered and Blindness Status Effects10/15/20 % faster.
The perk says that the survivor recover faster. That means:
Way 1:
You take the time (40 seconds) and take off 20% = 8 | 40 - 8 = 32 seconds. It stacks, so you have to take from the 32 seconds again 20% = 6,4. 32 - 6,4 = 25,6.
3 Vigil: 20% from 25,6 = 5,12. 25,6 - 5,12 = 20,48
4 Vigil: 20% from 20,48 = 4.096. 20,48 - 4,096 = 16,384
This is one way. I would say the correct one of the perk description.
Way 2:
But behaviour calculate it like this:
No vigil: 1 c/s = recovery rate, 40s for recover.
1 Vigil: 1c/s + 20% = 1.2 | 40 / 1,2 = ~33,33
2 Vigil: 1c/s + 40% = 1,4 | 40 / 1,4 = ~28,57
3 Vigil: 1c/s + 60% = 1,6 | 40 / 1,6 = 25
4 Vigil: 1c/s + 80% = 1,8 | 40 / 1,8 = ~22,22
There is a difference from nearly 5,5 seconds and you see the perk description is completly misleading. Maybe it can be changed like this, if the second way is the correct one:
You and your allies within 8 metres of range have a 10/15/20 % increased recover rate from Exhausted, Haemorrhage, Mangled, Hindered and Blindness Status Effects.
If you really wanted that the perk reduces his time around 20% you have to calculate like Way 1 otherwise everything is fine and a description change would be great.