Question about warbringer passive/block stuff

Turtle charm.

It says my passive shield blocks all damage. Understood it's like having raise shield up 75% of the time but also covers magic aoe, dots etc (probably whatever)

The second part is I noticed if I swap around my merit of service to the shield that gives mana/life on Block for a few moments when my allies blocked from merit I would also get hp/mp

This led me to question is the passive block I give with merit of service tied even more to my passive? I.e. if I used turtle charm am I passively also giving the party 75% chance to negate everything or just a standard 75% block chance (I was told it didn't effect projectiles yet I have seen it do this)

Granted I have 2 warriors I'm testing with the turtle charm and the other one for boosted passives

I was wondering this too. I guess you need to test it. Grab turtle charm and a friend and a tier 1 map. Look for a mage with aoe spell and have the friend get hit on purpose. I would be very interested in the results as well. I would be willing to help test if you need someone.