Good points about them being commonwealth in the past.
We could make ethnic regiments in the past that catered to a certain group because those people were joining the Infantry in droves anyway so it made sense.
For those of you in the Reserves in a large city who think that is a representation of what Reg Force units are like and we're a massively diverse Infantry, I've got some news for you.
Despite equal and accommodating hiring practices, a Reg Force infantry unit is still made up of predominantly white males. Yes you will still see a few women, black, and other non-whites, but the truth is what it is and without knowing the exact numbers I would not hesitate to bet it was over 90% white males.
What does this mean? It means that the Infantry brand is something that white males buy into. And if we start watering that down (the brand, I don't mean the race), it means we will lose our target market.
If we start messing around with units in order to make them more diverse, it would be like Chevrolet starting to market the Corvette toward old women instead of middle aged businessmen. Do you know what would happen? Yes, they might sell 100 more cars to old women, but they would lose 10,000 sales because their target market would see the commercials and think "wow, that's really not for me".