If you want good teamplay, get your clan onto teamspeak, get someone to call the shots. But trying to solve it by artificially supporting only "certain" strategies, no thank you.
Best team with best suitable strategy depending on terrain and team composition should win.
If you pressure the players into a certain playstyle or strategy, you take away freedom of choice and also would not gratify those who actually out of their own choice would try team work. From the chaos priciples you can also say that teamwork is not always the winning factor, we have seen it often enough. On the other hand banner stacking of really good players, not because there is so much effort of teamwork and coordination pfff, does give advantages. Gank squads in EU1 often clash against each other and whoever gets lucky there will then gank further, teamwork i dont see there as major factor either, but who gets to gank whom first and therefor could overwhelm others afterwards and that in the shortest amount of time possible.
With more and more high level players and less and less lower level players, you also dont value so much anymore a few heros, only numbers count, if your nostalgic gets you thinking about these past moments where your team won, with a few tincans upfront and lots of others behind waiting if your own teams tincan would win or if the enemy tincans would at some point rush in and rofl stomp the remaining lightly armored and lower level and often not very experienced players ... these times wont come back as most of the peasents nowadays are fake peasents trying to gut you 
and being able to.
If you want more players in the community, advertise the game to reallife friends and family or to those you play other games with or wait for the next steam sale.
While camping at times may still work, mostly due to flags it doesnt anymore or not for the whole map. That i see as a good thing. Flancing already has become nearly impossible due to ranged investations even in small groups while it may still have huge impact when successfull. Taking away the XP from flankers will make them obsolete. GG
What we have atm is often already what we had with the XP Barns, 2 big blobs clashing against each other. That you see people trying to get away from these mega blobs has different reasons though.
Who wants to be all the time in a clusterfuck of teamhits? Who doesnt want at times a duel situation, even if interrupted at a point? How is it that these blobs are mostly close to structures? Why are open terrain maps often so dreaded(hint: all HA/HX in one team or even most of ranged in one team, or all cav in one team)
For me not the XP system, but the team balancing system is what really needs some love!
autokick leechers
The time and amount of energy put into the XP system could easily solve that problem.
Kinggrimm, it's not the introduction of new players that is the problem; it's the player retention. The fact the game is so hard right out of the gates discourages many people to even continue playing to the point of maintaining this as a mod/game worth keeping.
When I joined during the proximity system, the thrill of being close to the fight was there, now it is not a requirement. People want to play and not get destroyed, so staying away from the fight while gaining ticks is the common strategy now. That, or they just run directly at the enemy team and get destroyed just to get it over with. There's no thrill or excitement hence no reason for new players to continue struggling through a game that only caters to "the determined" or "masochistic."
To address most of the posts in here regarding some form of "hybrid" system, I do like that approach. Given that time and effort have been put into the tick system, I'm sure accommodations could be made to re-engineer one type of /xp gold system or the other for the purpose of taking the best of both worlds.
For example, the hybrid system would feature proximity based xp/gold gain, except with the addition of team multipliers for wins, and the reset of the multiplier for losses. Valor could continue to be based on damage output, since it really solves itself with a proximity system; the highest scoring individual(s) would HAVE to be in the thick of the fight in order to deal that kind of damage (instead of cherry picking on the outskirts of buttfuck nowhere).
Of course, adjustments should be made to accommodate the current gameplay culture of the community: the xp/gold "ring" would be made multiple times larger than it was (used to be small, aroudn 25 feet = 7.5ish meters from the point of death) to accommodate the "strategy" that is currently favored by the sneaky snails/ ranged.
Further, I believe this was what it was, but the xp/gold gain radius was relative to the
killer, and not the death. So if you stood next to an archer who made a kill, the "suporting" xp/gold would be issued to the person next to the archer, too. This could also serve to make the game a little more central around the archers in the early game (where both teams are closing, but haven't made melee contact), who would feel left out should just the "strict" proximity system be used. Some kind of solution would have to be formulated for archer kills from a mile away (1.6km) while the victim was in a fight with teammates, since the battling teammate should be considered the 'supporting killer.'
Personally, I think that the xp/gain should be equal to every teammate within the xp/gold ring, otherwise that would encourage killwhoring, instead of teamwork.
Population ebbs and flows: Changes in server trafficFinally, the most glaring problem I see with a proximity based system would be the population in and of itself. If the server numbers are low, then the resulting xp/gold gain would inherently be low. And during prime time, the gain would be significantly higher. This, in my opinion, would amplify the peaks and troughs of the in-game population, given the current active player base: down times will see almost empty servers, primetime would probably see a full server. HOWEVER, this also means that siege would see more love, since it's more fun to dick around in siege when the population is low.
And perhaps the swell of server population density around peak periods would encourage newer players to frequent this game, especially since prime time is really when the most casual players are free.
