Thanks for clarification, if I could summarize:
V2: casualties simply get to fire back if a destroyer is present
V3+: first strike is removed if opposing side has a destroyer
@Cernel regarding LL, with two rolls against a 4:
1/9 chance for 0 hits
4/9 chance for 1 hit
4/9 chance for 2 hits
The odds are really good you'll get at least one hit, if not 2. With just one roll, you have a 1/3 chance for the 2nd hit, with the two dice you have slightly better odds for two hits. That means in LL, when attacking a naval fleet, you'd expect more often to have more casualties attacking with 2 subs and a bomber than you would 2 bombers (even though the attack power is the same).
Personally I think a big misnomer of LL is that players reduce risk and/or are not playing odds. With subs, fighters and surface fleets, in LL you can get 3 hits with an attack power of as little as 8. Meanwhile a defender if rolling together will not have a chance for 3 hits until you get a power of at least 13, and below 12 there is a chance to have only one return hit.