As long as a particular strategy (or commander) completely trashes all late-tech options of a particular faction, this is an abusive strategy and needs to be corrected.
Call-in meta does that indirectly in 1v1, as it completely prevents players from even investing resources in teching up. Call-in meta is abusive and, sooner or later, is going to be corrected.
Heavy-TDs do exactly the same for USF and Soviets. OK, Soviets can build Katyshas, so they are not
completely useless.
USF is completely fucked, however as, by the time of heavy TDs, there's also King Tigers and Brummbars around, which also hardcounter their infantry. This forces USF players to almost always go for an artillery doctrine.
This leads to stale meta.
Due to the choice of late-game options for Soviets/USF, there is absolutely no amount of changes we can do to either faction to overcome this difficulty, unless we start adding bullshit.
Third: you say both the jagdtiger and elephant are over powered in team games.
I disagree and here's why:
They are purely AT units with zero anti infantry capabilities. All three allied factions have very reliable infantry with tools to deal heavy damage to vehicles including satchels, AT nades, gammon bombs, flares, piats, and zooks.
That's why both units will be given either a cost decrease and/or some anti-infantry capabilities.
Sure, if you always play Brits (because, fuck Soviets/USF) and you always go Hammer (because, fuck Anvil), then, yes. Perhaps you have the right tools to play keep-up with Super-TDs (not 100% sure after Hammer nerfs, though).
So, I'm curious. When you play as Soviets or USF, and you encounter either the Elefant or the JT in 4v4, and somebody else in the team has fielded either a Brummbar or a King Tiger, how do
you counter that?
If your only answer is "oh, I don't have to deal with that, because I pick doctrine X", then this proves my point.
If the only counter-pick to a strategy is forcing a particular commander choice, then you have a self-reinforcing dominant meta.
I have nothing against you, if you are OK with using Jaeger Armor Commander, day-in, day-out. However, what's not OK is to expect it's OK to limit other people's choices when they have to face Jaeger Armor.
I do not want to deviate with this topic, but the danger of the artyfest in teamgames is due to the flares, laser scan, planes, because:
Infrared halftrack doesn't belong to non-doc OKW because it is so situational. A better idea would be to move it to the Overwatch commander (and merge the passive abilities), or swap it with the Goliath.
Nerfing the Calliope is required but at the same time USF need an Arty dealer late game. I'm afraid that nerfing it would make the USF faction completely helpless on teamgame.
Do you think moving the Priest stock would be possible? it could be nerfed a bit, disabling the crew option, it could also requires all officers to be bought before being unlocked. And that would make any other USF doctrine much more interesting.
USF have pack howitzer, the M8 scott and the Major for that role. USF late-game is its own can of worms, and needs to be fixed in relation to 1v1.
Nerfing Elefant/JT means that the only non-doc scout unit of USF (M20) will no longer get oneshot. This already means that there's something that can provide vision for the delicate Jacksons.
Even though that won't solve all problems, that could be a start.