Rugby does not have a helmet (except for the padded ones) and yet they still have concussion issues. I think there’s no clear answer although I agree about removing face mask.
Rugby players just don't deliberately go in with their head for the tackle, which is something you often see with NFL players (some NFL teams have experimented with helmet free tackling practice and seen it improve the game-time tackling effectiveness)
The lack of a stop of play after every tackle in Rugby also tends to ensure players are opting for tackles that they can recover from.
In American Football the expectation is for contact / hit with every play. Contact is just a staple part of every single play for every player. In Rugby, contact is largely down to those with the ball, and those specifically attempting to tackle them. It's a very different contact profile, even before you consider things like helmets and padding and what that does to the mindset of the players.
On occasion players will still land badly or be tackled by multiple opponents. Studies are a bit rarer, but older players doesn't seem to nearly have the same level of issues as players from the NFL.
Increasingly, the take is that pre 12yo kids shouldn't be having any blows to the head. Having a helmet likely doesn't help that much until you get to the point of a major hit.
So I do not think your data means what you believe it means. There is a reason they call NFL "Not For Long".
I would not let my children play either American football or rugby, existing options like basketball or tennis. Luckily most of the world plays soccer.
> For each of the sports, they looked at concussion rates based on minutes of athletic exposure (AE), which includes competitions or practices with the potential for injury. The overall concussion risk across all of the sports included in the analysis was 0.23 injuries per 1,000 AEs. By comparison, the concussion risk per 1,000 AEs for rugby was 4.18, while it was 1.2 for hockey and 0.53 for American football.
https://www.reuters.com/article/us-health-concussion-youth-s...
So on the one hand: research.
On the other hand: soccer (especially with sense enough not to be hitting headers all the time), has stupendously less physical contact than rugby or "football"... how could it be more damaging/dangerous with less contact?