Does anyone know why it is that the candidates always do everything in groups? in the Dubai episode for example they could have been a lot more efficient splitting up further, they didn't need to go into every deal mob handed, they didn't need three people to wait for a flag to be made for an hour and a half (arguably they didn't need anyone to wait for an hour and a half while the flag was being made but that's another issue)

Is there some sort of restriction on how many groups they are allowed to split into for the purposes of following them with cameras (there never seems to be more than two) or are they just a bunch of wimps who can't do anything on their own

Yes, we assume they're restricted because of available camera crews and transport. It wouldn't work in real life but in the show that's how it's done.

It's simple logistics, really. Each team is followed by just two camera crews and they travel around in two people carriers and are given two phones. Of course it would be more efficient to split up, but that would make the production of each episode much more complex (and expensive).

There are a lot of other restrictions behind the scenes that we never see. For instance, this week both teams went to the Dubai Mall. There are about 70 malls in Dubai, many of them much closer to the hotel than that one. But both teams went to that one. Yes, it's the biggest one in the world, but it's also the one where the production team would have secured a permit to film inside in advance. You can't just wander into anywhere with a camera crew on spec and film, not least for security reasons. Everything has to be set up.

Bear in mind that Nick and Karren have to divide their time between both sub teams