Stuka is made for killing, garrisons, team weapons and blobs, it is not a counter to anything. Even a not braced emplacement won't die to a single stuka salvo and would be repaired before the stuka barrage is charged again. LeiG is the best emplacement counter available to axis factions already. Its non-doctrinal, affordable in manpower cost, costs no fuel other than most emplacements and is buildable early on. The only thing thats wrong about this line up is the british commander with counter artillery fire in the smaller game modes like 1vs1 ans 2vs2. But they already searching for a solution as you can read in the current balance preview mod notes. So OKW doesn't need Hummel to counter emplacement.
LeiG still get outranged by mortar pit pathetically tho. and you need at least 2 to reliably dish out DPS to actually kill it, which makes it so stupid.