Combat Commander Archivist
Move! Advance! Fire! Rout! Recover! Artillery Denied! Artillery Request! Command Confusion...say what?!
I assume that bunkers (which are always face up) must be handled the same as face-up tanks in regards to rule 6.3. Otherwise a bunker effectively masks other units in that hex from damage (unless the unit is of larger strength than the bunker).
Sure, you have to target the bunker specifically to hit it. Otherwise any other units take hits, highest strength first.