An interesting item from overtdefense.com concludes with this:

A US Army study conducted in the 1990s concluded that the Army’s current 9-man organization was too small for the fire-team structure it adopted and that the army should either repurpose the squad to act as a single large fire-team within a platoon or raise its strength to 11 men. These recommendations, however, were not acted on at the time. Currently, the US Marine Corps are experimenting with 15-man squads but whether the US Army’s current study will lead to any change in squad organization remains uncertain. If the NGSW program is successful in selecting two new infantry weapons it will be fascinating to see how the new weapons’ weight, capabilities and ammunition requirements shape the future US Army infantry squad.

This issue is always the size of the transport and to what extent they want to change their organisation depending on the available transport.

3x 11 Man Squads in a 6x Bradley platoon? 

Having looked into the different squad size studies throughout history, I find they often make compromises based on factors other than effectiveness (cost, manning, etc) based on the realities of the budgets and desired number of divisions, and then design the vehicles around those compromises, thus ensuring there's no practical way to ever up-size them in the future without eye watering expense.

IIRC most T&E points to an 11-13 man squad being "ideal", keeping in mind this was done assuming only voice communication and before advents of things like PRR commo, so much larger and it becomes unwieldy.  We've gone into it in detail here, but I tend to echo E5M's sentiments and if I had my druthers we'd see 13-19 man squads.

Jeff (Jefffar) said:

3x 11 Man Squads in a 6x Bradley platoon? 

The US did try something similar originally (3x8 in 4 vehicles) but found a squad really needs to travel in the same vehicle. I think that is the basis of the russian 7 man squad. 3x7 is the smallest functional organisation that can take 3 SAWs and few casualties and still work.

The Chinese organisation of a 9 man squad with 2 RPGs and an LMG seemed insane but also worked. No idea what they use now.

Red7272 said:

The US did try something similar originally (3x8 in 4 vehicles) but found a squad really needs to travel in the same vehicle.

Well i I was thining a 5 man fireteam in each veichle, with squad leaders and platoon leaders filling in the extra seats

Jeff (Jefffar) said:

Well i I was thining a 5 man fireteam in each veichle, with squad leaders and platoon leaders filling in the extra seats

Yup. Except 5 men implies a 1 man SAW who has to operate as part of the fire team. With 7 men you can have a 4 man fireteam a 2 man gun team and a floating leader.  This makes the 22 dismounts effectively an oversize section with a lot of organic firepower and the bodies to carry it. 

I saw in a tweet regarding L400.3 that the 8 dismount requirement was based on the 2x4 section. This has now been supplanted by a 3x3 section, at least for mech. One fireteam is the IFV crew, with  2  3-dismount fireteams. Fireteam weapons unclear but I’d guess F90, F90GL and F89 or Maximi.

DavidPawley said:

I saw in a tweet regarding L400.3 that the 8 dismount requirement was based on the 2x4 section. This has now been supplanted by a 3x3 section, at least for mech. One fireteam is the IFV crew, with  2  3-dismount fireteams. Fireteam weapons unclear but I’d guess F90, F90GL and F89 or Maximi.

That is straight from the German organisation. Though apparently they use Ad Hoc organisations rather than 2x3 fire teams. I think the Danes did something similar but they did go with 2x3 fire teams and the M60 as a SAW. 6 men has been standard with the Germans at least since the 1970s and the Marder.

Just spent a few minutes trying to find an organisation for their Jager sections but no luck. They had larger transports and appear to have used the 9/10 man squad. No idea if they have gone to fire teams but a superficial look at photos show 3 man groups, though they might just be panzergren.

https://upload.wikimedia.org/wikipedia/commons/c/cb/STAN-1.jpg