If I remember correctly I tried this in a campaign of my own (never released), and I did something like this:
First I saved the status of each group member like you have at the end of the mission. This assures that their weapons, names and damage levels are saved. After that, what I did was I saved a variable for each unit using saveVar, and then simply used that variable to determine whether they'd show up at all or not! I.e., I put it in their Condition of Presence field. So as so:
//Code run before mission ends
U0_var = Player saveStatus "u0"
U1_Var = u1 saveStatus "u1"
U2_Var = u2 saveStatus "u2"
U3_Var = u3 saveStatus "u3"
U4_var = u4 saveStatus "u4"
U5_var = u5 saveStatus "u5"
U6_var = u6 saveStatus "u6"
U7_var = u7 saveStatus "u7"
U8_var = u8 saveStatus "u8"
?!alive u1 : u1alive = false; saveVar "u1alive"
?!alive u2 : u2alive = false; saveVar "u2alive"
?!alive u3 : u3alive = false; saveVar "u3alive"
?!alive u4 : u4alive = false; saveVar "u4alive"
?!alive u5 : u5alive = false; saveVar "u5alive"
?!alive u6 : u6alive = false; saveVar "u6alive"
?!alive u7 : u7alive = false; saveVar "u7alive"
?!alive u8 : u8alive = false; saveVar "u8alive"
(You could also just make the !alive etc. more simple by adding an eventhandler or somesuch to each unit and saving their status that way)
Then, in the init.sqf, I'd load their statuses normally, but each unit (in the editor) would have a Condition of Presence which determines whether they showed up in the first place or not -> i.e., Condition of Presence: u7alive
Naturally the u1alive etc. need to be defined as =true in the first mission.
NOTA BENE: The persistent campaign system in ArmA is not very intuitive, and can be broken quite easily by the player. For instance if the player at one point decides he wants to return to an earlier mission using revert, that mission will now be using all the vars saved in later campaign missions! Meaning, for instance, that your soldiers will be equipped and dead/alive as was apparent when the player last stopped playing. The only way I can see to overcome this is for each mission to have their own saved variables and loading them as that.
Second NOTA BENE: Using Spooner's solution might fix things, but it might also break them: the 0.5 second wait might cause the dead soldiers to show up in the briefing screen, alive and breathing and capable of being equipped, only to disappear (with all their ammo and such) once the mission starts. Just a caveat lector.
Good luck!
Wolfrug out.