The majority of why this is such a issue currently is simply due to population and the current population trying to chop down what ever their opponent is currently using as their last leg via mechanic changes. There should be no doubt in anyone's minds that both sides use multiple accounts and at this point most likely to the maximum benefit on both sides.
Two years ago fleets were running at a 20-40% second account rate to players. This problem is only exagerated with population issues because the type of gamer who will perform this tends to have more of a vested interest in the game and thus may stay longer. This style certainly makes staying in a game with population issues much easier as you can handle all tasks in-house on your own easier than finding the right people to perform those same tasks.
The second we have population and these tasks are performed by individual players then the benefits of multi-accounting begin to waiver and eventually become more of a handicap than a benefit.
Existing Counters
INTERFERENCE..........
Population.....
Speed fits.....
e-war....
Moving....
The only logical changes that could or should come from this are to take a look at and review 'fire and forget' fits that are able to approach a target and require no user interaction to win the fight beyond approach.
Closing
Anyone who still log's in and plays this game is only building to have a further advantage over the new players coming. Because it doesn't matter if its 1 guy playing 5 or 5 guys playing to killing the 30-50+ new players. Then if they do manage to finally take you down after a few attempts you have another couple hundred fit HM's ready to go. Once they finally spec in to a color of mech though to counter or play together you have such high extensions and war chest you simply rotate your fleet composition to counter their new numbers thus continuing the land slide victories.
New players or single account players will always be crippled until they have the EP and gear to run the proper fits to beat the "cheese" mutli-account fits. It is easy once you have that knowledge and ability but the power to it is the ignorance of your enemy.
The biggest issue really is having the industry to supply your combat with mutli-account play because If I have 4 guys who run 4 Rivler Mk 2's 2-3 times a week I would be hard pressed to get 30 or 40 guys who could produce those same numbers to fuel our PvP regardless of population. Let alone having the infrastructure to support and manage that many players properly to compete until the majority of them were in near maxed Rivlers.
Undefeated 2013
"Even alone you probably are one of the best" - Khader Khan
"Lemon the 1 man army .... also know as: THE TERMINATOR!" - Obi Wan
"There are people who are just better then you at doing many things at one time, some are far better then myself, far better." -Merkle