Why limit yourself to one company? It is a self-imposed rule for any non-sponsored player.
Maybe you really like a ton of Company X stuff, but there's just a couple slots that Company X can't fit right for you. Maybe their putters don't inspire confidence in you. Do you try to adjust to discs that aren't right for those slots? Do you give up Company X and move to Company Y completely who can fill those slots, at the cost of the old discs you knew you loved from Company X.
Use whatever individual specific discs work for you. Its not as if each disc made by a single manufacturer carry some specific mojo that you have specialization points in. Discs from company are as varied from each other as they are to discs from another manufacturer for the most part. Get a disc, learn that specific one (another just like it may not fly just like it) and love it.
We tend to look at single manufacturer bags as a statement of loyalty and commitment, not as advantageous to our actual game. If you really respect Company X as a business, by all means support them by buying their stuff. If you find Company Y to be shady, maybe don't buy from them on principle. If you are indifferent to Company Z as a business, but they make a sweet disc, buy it simply because they make a good product for you.
I carry 5 manufacturers with no regrets. Some of the companies I prefer over the others, but I love each individual disc as a stand alone unit. I wouldn't give that up. There are other companies that I like, but don't bag, no biggie. Go with whatever has worked for you ... because ... it has worked for you.