Automated team switching and the like is not the answer. I do not play Charlie much so it might be better to ask this question to the players that do, but when have I ever kept silent due to lack of knowledge?
My guess is that DoD:S players that play Strand do it for reasons that differ from players of other maps such as Ava and Donner.
Charlie game play is removed from the norm of DoD:S. I am not saying that everyone who plays Charlie/Strand do it for a "historical feel" or to get points or high K

ratios, but when I am there I do see the same people playing on the same sides. So my guess is that the people who do play for those reasons tend to gravitate to a map like that one.
That in mind the only way I see improving it without losing pubs would be to "PROMOTE" teamwork. There is no way to mandate teamwork that would not result in people leaving the server, but having eGOs and eGs and es on the server playing on Allied work toward getting people to communicate and play as a team is a good idea.
Suggestion
I have wondered how our servers, especially this one would do it they were switched to all talk and we promoted the use of our Ventrilo server for teams. There are pitfalls with this yes, but I believe it would be worth a try as we not only promote working in a unit, but we get public members into our Ventrilo server chatting with members.
To this end maybe we could setup a trial run for something like this where we setup a few vent rooms for Charlie/Strand. Members playing on the server would then let players know that we have vent rooms setup for it and give them the info. It would be easy to add the Vent server info to the server messages. It would give it more of an "epic" feel in my opinion. Charging up a beach with with your team in Vent, I think some pubbers would dig that. Just a thought.