I’m getting a little drained of this issue filling up the forum, so I’m going to help save the day for some of our fellow FIFA forum brethren, but mums. I’m sure this will anger the FIFA Illuminati, and I'm not completely sure why I'm giving it away for free, but I do know that I don’t want “them” to nerf the defense. If they do that it will be a bloodbath at higher levels. It is perfectly fine; you just need the right solution. You can name a squad after me (meatglue).
Short of players that hold the ball all game in their end after going up, It’s kind of simple to fight the 4321 “PTB”, plus most of them aren’t actually playing PTB. They are playing a low (25 or less) and passive (35 or less) line with the wings on stay back, but have their attack high- like 90/90. If you’re getting ripped by I complete noob that is just throwing on PTB, that’s all on you. As they say “GG” or at least get better.
So, with the offensive work rates of most wings-backs being high-ish and with 90/90 build-up there is a small window of attack. It is basic physics- they can't defend areas they're not in, especially since it's a narrow formation- there’s no wide mids. So, you counter-attack (aerial works best) their counter-attack with over-the-top passes to the wings from well passing WB and CMs, and get behind before their WBs are back in place, and long before the CMs return.
Next, there is some basic math at work here- you load their box with more offense then they have defense. The 433 will work well for both, but you have to send at least two CM's into the box (get forward). So, you send in your front three, plus two cms, 3+2=5 vs 4. The 433 (2) works well because you're still defending with 5 to absorb the counter attacks. You can go agro and send six in with other 433 formations. It's important to still stay, somewhat, wide to spread the backline. As wide as you can to create space. Plus, you need to leave space for your CMs to move in to. So keep your wings forward, balanced, GB, edge of the box. Keep your movement limited and rely on passing in order to keep the spacing. If you do too much moving in towards center pitch you’ll compress your team and the D.
Another wrinkle you can add to this, is to set your ST at F9, and use CAMs and/or CMs with high offensive WR and good finish- most times your F9 ST will pull one of the CB’s out of position (BTW you can do this with the 41212 formations and put both ST on F9, it will leave your CAM unmarked most of the time. (All this plus a bonus, good times!)
So, LB covers LW, RB covers RW, CB covers ST F9, and that leaves one CB to cover two CMs. You will always have someone open in or near the box, with plenty of space to move and pass. Plus, they can’t strictly depend on auto defend at this point. You can, also, get super-loco-loopy and set one back to overlap- one back, three mids, and three forwards. The counter-attack may kill you, but once you’re up 2 or 3, you can switch your tactic.