Can you gank and attack from base at the same time?

Yes, you can move units from your base and units with Ganking from another battlefield to the same destination simultaneously.

According to Rule 143.3:

"Players may perform multiple Units' standard move simultaneously... When a Move like this is declared by a player, the units' Destination must be the same... the Origins do not need to be the same."

How it works:

1. Declare the Move: You choose the destination battlefield.
2. Select Units: You select the unit(s) at your base and the unit(s) with Ganking at your other battlefield.
3. Pay Costs: You exhaust all units involved in the move simultaneously.
4. Arrival: All units arrive at the destination at the same time. If this causes the battlefield to become contested, a single Showdown/Combat is triggered for the entire group rather than separate ones.

Key Nuance: Ganking is not a separate "special move" action; it is a passive ability that adds a new permission to a unit's Standard Move (Rule 736.1.c). Because both the unit at base and the unit with Ganking are performing a Standard Move to the same destination, they can be grouped together into one simultaneous action.