I tend to dedicate specific pipes to Virginia blends, but I am not as particular about dedicating a specific pipe to a specific Latakia blend. In my Lat pipes, I tend to smoke a variety of blends.
Also, I have an Olivewood pipe I have dedicated to McClelland Drama Reserve.
Keep in mind, when you smoke a pipe with some cake buildup, you are smoking the cake, in addition to the tobacco.
Since I tend to enjoy well aged Virginia's, I am more particular about sharing different Virginia's in a single pipe.
This is simply due to the fact that it takes more time to properly age straight Virginia's, than it does to age Latakia and Balkan blends.
I haven't always been this particular, but as my pipe collection has grown in size to around 225 pipes, I now have the flexibility to dedicate a specific blend to a specific pipe.