|Lau Bannenberg Venture-Agent, Netherlands—Leiden aka Ascalaphus|
Somewhat unclear, but I'd say yes. Myrmidon robots originate in the Inner Sea Bestiary, which says the following about force fields:
Force Fields: A force field sheathes a robot in a thin layerof shimmering energy that grants a number ofbonus hit
points that varies according to the robot (typically 5 x the
robot's CR). All damage dealt to a robot with an active
force field is reduced from these hit points first. As long
as the force field is active, the robot is immune to critical
hits. A force field has fast healing equal to the robot's CR,
but once its hit points are reduced to o, the force field
shuts down and does not reactivate for 24 hours .
To me that reads that while the field is up, hits are against the field first, and only when the field goes down do you start hitting the robot.
I'd assume that the field doesn't have hardness, isn't vulnerable to electricity, and can't be critically hit.