without speaking of the situation of specific gangs who managed their numbers to not be attacked, i really think 10 is a little too low.
It only gives 20 possible opponents (les if u re in top 10), and with 7 days delay to attack twice and a possible rage, it really doesnt leave a lot of choices!
Edit: my bad, i misunderstood. So we can attack same gangs as before, PLUS the ones in the +/-10 lvls from us.
Actually sounds good to me