Especially compared to American and British call-in arty, everything besides the Stuka bomb that can be called in by Ostheer players is underwhelming at best, or utterly useless. That doesn't justify the Stuka bomb#s current status of course, but it should be set in relation. It should of course be nerfed to a reasonable degree, but doing so without correcting the mistakes that led us here will make things only worse.
BS, the CAS loiter for 200 ammo is one of the best offmaps in the game, put that into relation with the P47 attack. The relation between the stuka bomb and the british air supremacy is already linked above. The german light artillery barrage may not be as strong as it's allied counterpart, but it's cheaper, can still destroy artillery in 1 go and comes down faster.
Each offmap strike packs quite the punch, however they all come with a an obvious warning which significantly reduces casualties by those weapons. The stuka bomb is the exception, for no reason.