Ju88 has 4 rearward firing guns that can concentrate on the same target that sits dead-aft.
He111 has 2 guns that could do the same, and there's question of how high the ventral rear gun can aim upwards to track a con perfectly "flat" and with the curve of the fuselage there's question how flat the dorsal gun could depress as well.
The Ju88a4 had a flexible nose gun which we don't for some reason. The He111 has this as well.
The only difference is the He111 has a single 7mm gun in a very small window with narrow field of fire to the left and right of the dorsal position. These were ineffective and often removed in the field. The 20mm MG/FF had limited ammo and limited range of motion (meant for hitting shipping targets as the bomber flies over, if I recall?)
So as far as defenses go, the Ju88 is faster with more ord (while being faster) and more likely to defend itself if attacked.
He111 is in no way better than the Ju88. It is cooler, though, and more important for many scenarios.
