Ok, I have problem playing as Ostheer vs Soviets to break their frontline.
Literally, no idea. I skipped Grens on purpose cause I had feeling like I will be dealing with mortars so static Grens seemed like a really bad idea, Assault Grens looked like a way better option to deal with support weapons but again, each attempt ened up with heavy bleed cause of mortars hidden behind all forces.
In last quote u practicly answered to your question my friend. In even battle of support weapons for most part looses that who tries to brake it too soon, cause unprepared attack leads to big bleeds. Take as an example real life - WW1 battles, how much bleed was taken by attackers when they attacked fortified line without proper artilery support. The only other way without pounding your opponent with massive rocket/schells is using tanks.
But before going into battle - value your strenght and weakness by comparing it with opponents.
OST vs Soviet in support weapons - more or less even (HMG is slightly better in OST, mortars - slighty better on SOV).
Whats with infantry : If opponent uses guards - then he is more or less even with u (or even a better position) - cause of 2VP and slightly bigger cost than grens, on other hand, guards has better utility in mid/late game.
So where u are better at - T3. OST has great tanks in T3, mostly sufficient in 1v1 to not even touch T4 - rather build another P4 + stug. If u need late game pounch, bring in Tiger. Just dont overextend, and flank + micro.
In resume - Action against prepared defensive line
1. Dont bait into traps by doing yolo attemps on mortars.
2. Smoke and flank (lol, i used it), but seriously u can bring at least 1 mortar for smoke support. Better still, if u dont like RNG battle, mortar vs mortar : use mortar HT, just keep it safe from ats/guards and dont Yolo.
3. If he pushes defensive line further, dont rush head on to save your precious 10 metres of no mans land, wait for opportunity and attack overextended line where it hurts most.
4. Combined arms - arty + infranty + tanks.
5. Dont use more than 1 ass gren, they cost way too much for what they offer, and they are only viable as flanking unit while all of their army is distracted elsewhere. Rember they doesnt scale in mid game, god dam even kubel has bigger utility by then if managed to vet1, as map hacking tool.
And actualy..... There is no 1 answer to most of the coh2 problems. As in evenly played 1v1 u have to value your resources, u have to thik further. If u rushed t4 and went for PWerfer u lost 2 P4s, and by that i mean 2 freakin P4s + who would come earlier with much bigger impact. On the other hand, if u suck with tank micro... Then.. U have to pund em back to stone age.
My dream would be play game to around 43 timeline, without GodMachines - KT, Comets, IS2 and so on... Cause for now only gamemode i see normal is 1v1 (and to less extent 2v2), the only place u can have combined arms, what actually ww2 was all about. In higher modes game practicly turns on SuperMega tank fest + who has better abilities. 
Good to help. If someone interested i also posted replay how to anhilate volk blobs.. SO far i managed to work on with 2 community issues - maxims and volks, enplacement commander is yet to come, i still cant get around it, all wins vs it are only because my opponent made major mistakes.
arnolaz
small bird with large arms
arnolaz
Nightcloud™
FLEX TAPE®
Relic Entertainment
