I never understood or agreed with splitting arenas. It has been quite detrimental to community continuity. HT argues that AH subscribership was stagnant and this was a fundamental impetus for growth. There is also the contention that one arena was somehow more conducive to country numerical disparity. While I obviously don't have access to the type of hard data HTC does, I lived and played through it. My subjective observations don't indicate any correlation whatsoever, nor do I really see a substantial increase in the number of players online at any given time. The difference between 500+ in AHI and 700+ players in AHII during prime-time over the course of several years can hardly be contrued as proof positive of the irrefutable success of splitting the arenas. Perhaps without splitting them, we may have had 1500 players nightly? Perhaps splitting arenas squandered what might have otherwise been gained from the marketing effort.
HT is a programmer and no doubt understands the fundamental truth that to firmly establish the cause and effect relationship of a phenomena and the suspected catalyst you must observe them in hermetic isolation from any other potential causal factors. With regard to the split arenas, this was not the case. The arena split occurred in relative temporal proximity to a target market focused marketing campaign, the release and rapid post-release tuning of AHII and the very aggressive implementation of the ENY limiter which was subsequentally watered down somewhat.
The paltry increase in players, mostly of the younger demographic, could more realistically be attributed to the simple fact that home computers of sufficient power to run an aging game like AH are relatively cheap now and in more homes than they were when AHI was cutting edge and they were prohibitively expensive, especially to the younger, non-hobbyists not so financially well endowed as the established niche customers.
What I see since the arenas were split is a lot of country stacking. A country, usually by virtue of a few large squadrons with dubious ulterior motives, will consciously stack one arena, usually to the point of the hard cap for the purpose of resetting it or farming it for captures/score/rank, etc. This is especially obvious earlier in a tour and since the scoring of the LW arenas was segregated from the EW & MW. I also see a lot of people forced to do things they don't find fun, play on maps they don't like, miss playing with friends or some combination of those just because of the arbitrary cap. I see many situations where the cap actually hurts arena balance. For example, Orange has 100 Bish/75 Knights/55 Rooks. I want to join it and fight for Rooks, but I can't because Bish have stacked it and capped it, so the arena cap prevents me from helping balance it..
In general I just can't see any possible way splitting the arenas improves community continuity or enjoyment of the game for anyone. The only reasonable reasons to do it is due to technological & hardware limitations server side or end-user side or very small playing areas where severe player density issues arise. The vague justification that split LW arenas is somehow some sort of "snake oil" for what ailed AH prior just doesn't bear the scrutiny of direct observation. Certainly, if there is some benefit not apparent to the customers, but visible on some spreadsheet at HTC HQ, it's far outweighed by the very blatant negative repercussions...