You have no idea what you are talking about.
Bodyguard mode splits damage you take among your pets. That is all it does.
Defense lowers the chance you will be hit. The soft cap is 45% because Mobs have a base 50% chance to hit and minimum of 5%, so reducing it below 50% - 45% = 5% is pointless in most cases.
Fortify the pack increases the defense of your pets by 5% + 1% per stack of pack mentality. You slot it and it increases it more (Been a while, but 60% I believe). So 5 stacks add 16% defense to your pets. Add power boost and that puts you at an additional 24% defense. Top pets have 10% defense. That means the naturally get hit 40% of the time. With a power boosted Fortify w/ 5 stacks they are getting hit 16% of the time. Throw in Maneuver s and IOs and it is down to 5% of the time.
You do NOT want to play a Tankermind (Meaning tanking for your pets in body guard mode) with fortify in most cases because you are losing all the value of Fortify if you do.
Lets use an example where you have 3 pets. They have 10% defense., you have 0% defense We will use slotted Fortify but with 0 stacks which gives all your pets an additional 8% defense. There are three mobs that do 10 points each attack, and they will attack 10 times.
If the three mobs each attack a seerate pet, each pet will be hit 40% of the time (50% - 10%), and the average damage per pet will be 40 points, or 120 points total damage. You take 0.
If you are in bodyguard mode and you tank all three for your pets, you will be hit 50% of the time. damage is split 40% you and 20% each pet (easy math is why I chose 3 pets.) You take 150 points of damage total, but you end up with 40% of it, or 60 points of damage while each pet takes 30 points of damage.
Now add fortify with no stacks. Pets are hit 32% of the time (50% - 10% - 8%.) So each pet take 32 points of damage and you take 0. They are taking 20% less damage now then without Fortify. If you tank the damage, the defense (Nor resistance) of the pets will not reduce the redirected damage, so you will still take 60 and each pet takes 30. That is why if you use fortify bodyguard is not useful because you want your pets tanking the damage. (You can get enough recharge where this is permanent.)
Lets say that you want to use a power boosted fortify with 5 stacks. Lets do that math.
Now, each Pet is getting hit 16% of the time (50% - 10% - 24%). They each take 16 points of damage for a total damage dealt of 48. That is less than half what they normally take.
If you go hog wild and have Maneuvers, IOs and stack 5 times, you reduce the damage the take to 5%, or 15 points total.
If you use just Fortify with 10 stacks and nothing else besides their natural defense, you reduce damage by the same amount (roughly) as a 5 stack powerbosted Fortify.
I attached an old screenshot of when I was testing this out. This was with 0 stacks (which can be permanent) , and Powerboosted it is adding 11% defense. Even at that level I was sitting at about 36% defense vs 25%. In other words, my pets were taking 14 points of damage per 100 instead of 25. At base level, Fortify w/ Powerboost reduced damage by almost 1/2. Add some stacks and it reduces damage taken by 80% (25 points to 5 points)
As far as the part where it puts them in bodyguard mode....no it doesn't. I actually wasn't sure because I microed them anyway, so I logged back on and lo and behold, when I cast Fortify, they stayed in whatever mode they were already in.
And yes, you only see these numbers when you get higher level, but that is kind of my point. You complain that everyone else doesn't know what they are talking about when it is you that does not have the experience nor the data to know what you are talking about. You are using the text descriptions which are very vague. We are using in game numbers. and a lot of experience.
We are here to help, but stop talking down to us when you are not even right.