@SimpleJenn or 
@Ponypoor or 
@BY Bob or anyone else w/Polish ~ take this w/a grain of salt if not interested.
Just read BYC article 
Chicken bully/chicken victim - a two-sided issue & 
@Jsnick has Polish where her Polish got woefully scalped so rehomed the offenders & replaced w/ 2 EE's who she thought were gentle but the EEs are now the bullies to her 2 Polish (laying hens are real meanies! chickens in general can be very hostile as we all know). I keep sharing w/ owners about the tendency of gentle Silkies & Polish being easy potential targets by the full-size chickens but no one listens 

.
Silkies/Polish have varying shapes of open skull bone where the brain is covered only by skin ~ a perfect peck on the soft spot skull can injure, nerve-damage, cripple, seizure, or cause death eventually.
		
		
	
	
The Silkies/Polish learn to move fast from bullies but it's still a risk mixing open-skull birds w/ bigger full-size breeds. Must be why Europeans mostly keep their Polish a Polish-only flock & Silkie owners keep Silkies separate. If there are not a sizeable number of Polish or Silkies to form their own sizable flock the single 1 or 2 littles then hang out around the bigger birds & risk getting targeted.
Just my 2 cents from having Silkies & dialoging w/ breeders & other open-skull owners so don't be offended. If you've been lucky so far, fine. This is just potential info to be aware of.