This may not be of any help to you but this is how mine break down:

I very, very rarely smoke aromatics, so I won't waste a briar on them. I have 2 cobs with a big "A" on the bottom of the bowl, both straight stem. I believe you could smoke that stuff in a tuba or a straight 12 foot length of 3/4" pipe and that crap is going to gurgle.

For English blends I use pipes with a smaller, narrow bowl, because a little of that goes a long way for me.

All the rest are used interchangeably for Virginia, Va/Per, and burleys, though I tend to smoke burley in a cob more often than not just because I enjoy the flavor more.

Most of my pipes are straight stems, with a few 1/8 bend and two 1/4 bend. The shape of the stem doesn't enter into the decision which tobacco to use them for.