Ironically, this was tried once before, back in the 1960's...two brigades, the Highland & Lowland, were created and the individual battalions of the Scottish Regiments were placed in them...this was to bring the British Army up to the equivalent of the US Army during the Cold War...let's just say it failed miserably.

The regiments were forced to wear a single cap badge, and in the case of the Highland Brigade, it was a Stag's Head on a St. Andrew's Cross -- the Jocks dubbed it "The Crucified Moose", and the cap badges came back quickly.

Regards,

T.