I am surprised at how rarely the full team seem to be on screen at the moment. In these early stages, surely it's important for viewers to get to know the presenters and for the programme to bed-in with a bit of stability and consistency.
In radio, it's common when launching a new breakfast show for there to be a tacit agreement that the new presenter won't book any holiday for the first three months or so to allow the programme to establish itself. Okay, so there are some unavoidable situations, such as Ben being involved in Soccer Aid, but GMB having so many stand-ins so often can't help its cause.
Does it bother you? I doesn't bother me, I really like it with 3 people. Plus, Sean was presenting, just from Brazil. He still said the "Hi there good morning I'm Sean Fletcher..." at the
TOTH. It's like having Mark Austin presenting from another country on News at Ten. It's not a problem and Julie cope on her own at the desk... Let's not forget that on Good Morning Britain there is still 3 people at the desk, Laura/Alex and normally Richard in the studio with Andi doing his thing. So, Sean was presenting. And when Ranvir was at Stephen Sutton's vigil, it wasn't really a problem.
I don't see why this would be a problem. Nobody says, "I'M SO ANGRY AT ITV FOR ONLY HAVING 3 PRESENTERS AT THE DESK! IT'S TOO MUCH CHANGE AND I CAN'T DEAL WITH IT!

" or "RIGHT, THAT'S IT, I'M SWITCHING OVER TO BREAKFAST BECAUSE ITV ARE SHOWING THEIR COMMITMENT TO SPORT BY SENDING A PRESENTER TO BRAZIL." and nobody says "This is so upsetting. Why aren't Susanna, Charlotte, Ben and Sean altogether when this how has only been on air for a month and a half? I'm never watching this show again."
It's breakfast television for goodness sake! I don't care which presenter or how many of them are presenting, I want the news, weather and sport (and travel in my region) for the whole country and the rest of the world. I don't think the ratings are going to drop if there are stand-ins, or variations in the size of the presenting team. It's nice to have some variety.