Those two game modes are lost anyways, there are structural flaws that will never allow decent balance. The problems are:
1) maps are too large, meaning infantry play usually becomes obsolete at some point, it encourages blobbing and factions with a forward retreat point have a massive advantage in terms of infantry play
2) too many units on the field, which means that it is really hard to keep track of what's happening. With more players/units, unit preservation gets way harder. Also, more units = more cheese.
3) resource income is totally broken, gaining like 50 fuel or 70 ammo per minute leads to spam of tanks (which makes infantry obsolete) and call-in arty/loiters. In those categories the axis usually have an advantage, when one side brings elefants/JTs plus stuka bombs en masse, while the other side has to rely on comet spam and cancer cover.
Imo these points lead to difficulties in balancing those game modes. These modes should be seen "for fun" when you play with friends. I dont understand why people would play those modes on their own, maybe because they like those huge battles of attrition, dont know.
Those are the best formats, it's where the feeling of war is the best. it's also the hardest mode (4vs4 + automatch alone) because you have to cope with all kind of teammates.
It's just that all sides need to have the same tools to fights (some have better tools, some come faster but every one has something for any situations. All of this balanced to be fun.
We are not far from the good balance, just a bit more tuning on the more problematic units (The one being the most used and those that killed too easily without efforts)
Just keep doing the good job at balancing your are doing, til all formats are done.
Some more maps would be fun too.
It's not for everyone, but still those formats are the most popular.
That will keep COH2 alive and kicking !!!