in a 0.5 system you can gank freighters ( that arent tanked ) with 8-9 talos using t2 void ammo. The number of ships go up the higher sec status you are ganking in and ofc if a freighter is tanked then its going to take more but its perfectly doable i believe if you have 10 accounts. For 2 accounts only you will be limited to ganking t1 indys and cloaky transport ships.