I agree that the tactics can get a little overwhelming at times but the same holds true for FIFA (which implemented more detailed, and probably rarely used individual tactics for players). You couple that with sliders and the game can get overwhelming to some. I'll never argue against taking away options since folks can always just choose to ignore them.
Konami and FIFA need to get this stuff right out of the box but for gamers like us (me & u) we're willing to go that extra mile to make the game play better for us. That's why I was able to read/tinker with the tactics on PES 2015 to eliminate that space that drives you crazy.
Fluid Formation with a deep back line, a CDM in front of them, 4 MF's in front of them and a ST for an outlet/frontline pressure made my defense super compact and in-turn I gave up 20 fewer goals in YR2 of my ML and 25 less in YR3.
Fluid Formation (When in Possession/Attack) + Short Pass + Possession Game + Maintain Position (keeps your players from leaving their space while playing shorter safer passes) + Medium #'s in attack (doesn't over-commit too many players fwd, especially my CDM who rarely got close to the opponents box) +
Fluid Formation 4-1-4-1 (When NOT in Possession/Defense) + All out Defense (keeps your players behind the ball) + Middle Containment (forces the opposition out wide and makes your wingers tuck in) + Conservative Pressure (gives your opponent time on the ball but saves stamina/doesn't open up space by chasing) + Deep defensive line (help to curtail through balls) + high compactness, 8-10 (clogs the middle of the pitch) + Many for #'s in Defense (just add bodies to defense, mainly ST/wingers).
I know that's A LOT to ask of a casual player AND it doesn't always suit every situation (chasing a result) but it will cut down on open space just as long as you are disciplined as a player to not take your player out of his defensive zone.
The way the game is set up by default for WIDE OPEN contests because of the formations (far too attacking, players pushed too high up the pitch) and the tactics (too similar for teams/ lacking situational/on-the-fly options, and just flat at wrong at times).
Klash is one of the few people over at evo web that understands how the game works under the hood. You can tell because once the new game drops he immediately looks/posts about what tactical options have been added/removed. Much like 2K hired the Da Czar and Konami got Weedens to create their trailer they need to get someone like him on board.
I agree about the variations between teams but I think it's just down to laziness by Konami in setting up the tactics. Most of them are very similar to each other.
EDIT - I should have clarified Matt, I meant I had no issues with horizontal defensive spacing. Vertical defensive spacing as in my CBs being too wide was/is an issue that needs to be addressed by game coding/programming. You can place your CBs really close together on the formation but this has ramifications elsewhere.