Quail + Pheasant = Dead Quail.... Disease Isnt An Issue Since Both Are Susceptible To The Same Poultry Illnesses... So Mixing Pheasants With Chickens Is Just Like Mixing Quail With Chickens+ Much Bad Juju. As Well Both Have The Same Dietary Needs, So Thats Not An Issue. Same Is Relatively True Of Housing As Well... Behavior-wise? Now Thats An Issue!
Virtually All Pheasant Speces Are Way Too Active, Agile, And Agressive And Size Is On Their Side. The Results Would Be A 1 Sided Gamebird Form Of Genocide.
There Have Been Occurances Of Pheasants Killing Turkeys And Peafowl Through Violent Attacks.... The Lil Quail (even The Little Junkyard Dog Bob Whites) Dont Stand Much Of A Chance. Unless Being Housed In Very Small Numbers In An Aviary Thats Excessively Huge And Properly Structured Your Results Will Be Rather Unpleasant.