I dunno what Ostheer meta even is lol. I really don't go into games as them with a real preset plan of what I'm going to do (whereas as US, for instance, I might plan to go Riflemen into fast Captain into Stuart or something). It's almost always just me reacting to what my opponent is doing.
The only semi-viable aggressive strats that I can think of off the top of my head are Ostruppen spam or 222 spam.
That's what I normally go through when I play Ostheer. Most of the time, aggressive strategies are extremely painful to pull off for Ostheer, especially due to the British death machines known as 'emplacements'. Ostheer has the stopping power necessary to hold back enemies, but when it comes to offense, their only true reliable options are found in late game. By the time late game hits, you either are swarmed by the enemy, or you barely get by. Late game is out of the question if you fail to exceed during the early portion of the game. If you loose the early game, you'll be surely annihilated by mid/late game.
That's why I consider Ostheer to be the least forgiving faction out of them all (not to mention the low squad size). It's painful...