Specialization plays a significant part only in 1v1 engagements between two the same type planes. In this scenario the one with better equipment will get the advantage (disregarding human factor for the moment). However, a specced LF will still struggle to reach and chase a bomber (specialized or not), a HF will still not outturn any other fighter (specced or not), etc. Do you see where I'm going? Depending on planes participating, it's a matter of choosing what and when to engage. If one, in an unspecced (i.e. new and not fully mastered) plane pick up fights with specialized planes from the other team (especially of the same class, or the same type), the result is almost inevitably the same loss, over and over. It is the human factor, not the specialization in itself. If you have an unspecced plane that has a specced hard counter on the other team, you try to avoid that opponent; if you are in a specced plane, and there are no counters on the other side, you do whatever the hell you want. This isn't a matter of gear and equipment, this is the matter of tactics and strategy. It's humans who make or break the specialization in MM - by either being too overconfident in their ultimatet Spitfires or Yaks, or overconfident in their belief they can combat such planes.
If the other team has 2 or 4, or 6 specialized planes, it does not matter at all. What matters is what types are they, and can they spoil your own gameplan or not. If you're in a bomber, and the other team is full of specialized Yaks, you just go higher than their altitude and break out crisps; you choose non-obvious routes; you use bots command to get cover or diversion; you remember the basics of aviation and utilize either your energy advantage, or your speed advantage, or your superior firepower, or your better acceleration, or your advantageous stall/climb/dive characteristics, etc etc. This is what matters, and this is what I deem skill in this game. Anyone can and eventually will specialize his/her plane; not anyone can fly them effectively.
Many players need the edge of specialization to compensate for their shortcomings in skill. In such cases it is easy to believe specialization is the final gimmick needed. In part it is, as it will compensate for some things - but in itself, specialization has zero bearing on lack of spatial awareness, on bad gunnery, on ignoring plane's characterics, on making basic flying mistakes (like diving with full throttle and without using flaps/brakes - as WoWP allows - to maintain maneuverability). Some, and only some, items of equipment will do things behind the scene, that may elevate one's skill to some new level - an example would be Gun Sight, which introduces slightly higher values of auto-aim and lowers dispersion, thus alleviating problems that are on the side of the player (be it bad eyesight or poor ISP and lag impairing aiming). This however are crutches only. The gear will not make a bad player suddenly a world class ace. That's why a lot of players need an additional layer of 'insurance' to get their WR inflated, aka anchored flights. Gear in itself is just a gimmick. The classes are balanced within a certain threshold of characteristics; if a player keeps that in mind, and pick his fights consciously, gear can be totally negated.
Yes, this is a viewpoint of a very experienced player, of someone who flew them all (well, almost) and in various iterations of the game. Instead of dismissing it as such, I would imagine it would be beneficial to consider this as something of value. In my opinion it's all about the player and how he/she handles the gear that is at his/her disposal. For me indeed the amount of specialized planes on each side is irrelevant. Depending on the plane I am in, it may or may not impact my plan for the particular battle - and usually doesn't. If I need to, I will avoid the 'better' planes; if I can, I will terrorize 'worse' planes; if I need to, I will fly around the map being effective in what MY plane can do, and not trying to play according to THEIR strengths. Specialized or not, each plane can do certain things and can't do other things. That's the gist of it all, and not some abstract +3% better roll on a plane with specialization.
Is this an understandable explanation?