And what's the problem with going for A to counter B?
If enemy has Jadgtiger I must go for mss mediums.
If enemy is blobbing really hard, I should get 2 HMGs.
If enemy makes M3/Bren/222, I make AT Gun.
Etc...
And it's not even necessary to counter emplacements only with late game artillery. But it seems no matter how many posts are made listing various kinds of direct and indirect counters, it doesn't matter. To demonstrate that I'll do it again:
#1 - Use at least double mortars/leigs. They can destroy emplacements quickly and force them to be braced so they become ineffective and destructible without danger, while being very good against the bolt action rifles and machine guns of UKF too. They will wipe repairing sappers. Emplacements can't do anything to them if you keep a reinforce HT (PS: just making a flame halftrack will force him to go AEC instead of bofors, AND you can take out the AEC) at your mortars or a FRP not far from your leigs.
#2 - If you are Ost, make gren > sniper > gren > sniper and insert a mortar wherever if you need to take out a garrison, then select osttruppen/luftwaffe/CAS. If you selected ost, obviously make osts instead of grens. Move all your units as one while your pios cap. Drop fuel, which he can't contest because he has emplacements instead of units. Only get an mg42 if he starts making a bunch of flame engineers. Spend only as much manpower as you need to hold his units back and put the rest into caches, then skip T2 and get tanks which his emplacements are useless against and win the game. Alternatively drop munitions instead, make at least 3 halftracks to put all your units in, get schreks and a minesweeper, then drive into his base and upgrade flammen on 2 HTs & destroy his buildings to win the game, bypassing his emplacements entirely. Or use it to simply get multiple flammen HTs if he made a bofors (which he shouldn't have if you succeeded in your early game), force it to brace and drive in. If he made an AEC, make one flammen and use the munitions drop for schreks instead.
#3 - If you are OKW, make a kubelwagen and send it to cap the map (you'd think there would be no need to say the last part, but after I watched some casted replays...). Send your sturmpios not to cap any point at all, but straight into combat with his infantry section (this usually means sending them to his fuel point). Follow up with volks. Aim to simply tie his units down in combat (so stay behind cover) while your kubel caps the whole map, get an mg34 if he goes flame engineers, then do whatever you want to win the game as he has no vision, no positions and no fuel, and won't be able to put up emplacements in the first place.
#4 - If you are in a team game, fight as normal first so the Brit makes emplacements at his side, then double team the other one. If he makes emplacements at his friend's side then your buddy can hold position at his while you cap all of the Brit's points and send your units to help, now you have most of the map.
#5 - If you are in a team game, get Elefant and/or Jagdtiger. They'll take out both tanks and emplacements, the Elefant doctrine comes with great abilities earlier too and so does the Jagdtiger (example: Pzusilier flares = he will be under more pressure against them with their G43s, he can't hide his emplacement construction, snipers are revealed, and they spot for your leigs).
#6 - If he put his emplacements near buildings, get building spawn units. Force his bofors to brace with double mortars/leigs, which you should have earlier or at the same time as his bofors, and then attack. When he sends in a machine gun, spawn a unit and grenade-wipe it, and then walk over and wipe the other one.
Those are off the top of my head.