For anyone interested in how Rook helps Nasir on first-rez here's some data.
Only ICE Nasir cannot BREAK with Overmind on first-rez are (keep in mind some of these can be run through without a breaker, and this assumes about 3 power tokens):
Archer
Bullfrog
Chum
Hunter
Cell Portal
Neural Katana
Data Hound
Data Mine
Eli (can click through)
Inazuma
Janus 1.0 (unlikely without Deep Red)
Komainu (unlikely without Deep Red)
Hive (unlikely without Deep Red)
Matrix Analyzer
Rainbow
RSVP
Swordsman
Tsurugi (unlikely without Deep Red)
Viper
Wotan (unlikely without Deep Red, alternate methods ok)
Wraparound (without Fracter)
With a Rook on a server, this becomes:
Chum
Hive
Hunter
Swordsman
Wraparound (without Fracter)
Janus 1.0 (unlikely without Deep Red)
Archer (unlikely without Deep Red)
Wotan (unlikely without Deep Red)
Tsurugi (unlikely without Deep Red)
Think about that... If you have an Overmind AND a Rook out, only 9 unmodified ICE will bother you! Of those, only 5 ETR and of those, Wraparound, Tsurugi, and Hive are most likely to be seen.
On looking at the ICE data, Bishop is inferior to Rook in almost all cases. Knight is preferable as another way to deal with Wraparound. Hive is bad for OverMeidan, consider going somewhere else. Parasite seems best against Hive. Can remove one ACCT Siphon for a Planned Assault and put in a Parasite.