You saying 'No' means nothing. Fewer collisions = less trauma to the brain. It's not really something up for debate.
Trying to spin the issue by changing to leather helmets, no facemasks and limiting player weights is silly. Yes of course that will have a major impact on the way the sport is played. You actually thinking that it will reduce the amount of head injuries is again, silly. Players have learned to play the sport a certain way for many years; removing current helmets and facemasks suddenly will quickly result in some very serious injuries on the field. It's pretty obvious the way to go is better helmet technology, one that is designed to prevent concussions (with a focus of low-to-high blows) rather than prevent skull fractures (the current method, which focuses on extreme blows). It will probably be a helmet similar to the padded ones you see in practices but more advanced, with multiple shock absorbing inner shells and a softer outer shell.