Er........ I'm afraid I have to disagree with you there. It might be necessary for the fans who watch the show primarily because they like the main characters, and in the case of Daniel for those fans who absolutely adore either MS or Daniel, but for a military group, that consideration would be one of the last.
Let's not forget that in reality Danny, Sam and Teal'c wouldn't even be considered for a role in the SG1 team. It would be ALL professional soldiers. And while Sam is a professional military person, a woman wouldn't be allowed a place on a covert ops team, which is realistically what that team would be, no matter what her academic or military qualifications. Danny wouldn't be allowed BECAUSE he's a civilian, no matter what his anthropological, linguistic or archaeological qualifications might be and Teal'c wouldn't be be allowed because he's an alien and he would be off in a some lab somewhere being dissected.
The dynamics of a REAL SG1 team would be totally military, soldiers picked for their expertise at recconnoitering, securing and holding a potentially hostile and dangerous piece of ground. i.e. every single planet they gate to. And they wouldn't wander round this area like tourists looking for soil samples and artifacts or saying we are friendly explorers, take us to your leader. That would come much later for the 'specialists' once the soldiers had secured the area and made it safe for things like that and safe for the personnel who would be operating in the area.
When I look at the show and the way it has developed and then I go to the boards and see what the fans say, I realise that somewhere in the Stargate production team, someone has the task of trawling the boards and gathering fan opinion, because I have watched the writers and production team steadily bring this show into line with the desire of that group of fans who want the show to be totally about character development and relationships within the team or its peripheries (i.e. people in the SGC itself like Hammond, Frasier, Major Davies etc).
They have taken it way out of the original concept of the show, that the answer to the mysteries of human civilisation lie out there somewhere and that in order to find it the humans would have to overcome a huge, monstrous, powerful and menacing enemy who have held the galaxy in thrall for millennia. The show has now wandered into the realms of space soap opera where things like whether Danny is hurt or Jack loves/likes Sam enough to breach regulations for her or indeed whether the team care enough about each other to immediately rush to the ramp whenever one of them has a rough journey through and hurts themselves, has become the primary direction.
This is meant to be a roughie toughie ass kicking military team for god's sake, not a group counselling session/love in!
The desires of the fans have become clearly mirrored in the episodes themselves, and to bear me out in this, it seems strange that when a large group of fans started to complain about the whussy Season Four the Stargate people suddenly tried to come up with a less relationship oriented Season Five, during which the relationship loving fans subsequently groaned and moaned because now the team don't seem to care as much about each other.
I can only think that the writers and producers must tear their hair out on a regular basis.
Danny gets whumped because fans perceive him as the sweet blue eyed, handsome, young, nerdy, non military, non tough member of the team, as opposed to the others who are warrior types. It does make for a different dynamic, but gets very very wearing and tedious after a while. I imagine playing that kind of character and being treated like that by the fans has become rather tedious for the actor himself and I don't wonder at his desire to curtail the part.
I sincerely hope that the Daniel Jackson replacement is not the same kind of character.