To quote Tyler, "DME will transport anything that the airlines will handle." If you get 4 DME tags all with your name on them, you could use all 4 as far as the Disney computers are concerned. Hey, you could check 10 bags for yourself with your airline, you'd just have to pay the airline extra for it. There's no way for Disney to know if you paid your airline for a 3rd bag or not, so it seems like it should be smooth sailing for you.
NOTE: Make sure you're being accurate when you say "you" got 4 DME tags. Each DME tag has 2 names, the "master" or "main" name on the reservation, and also the name of the exact passenger/guest. So for my party of 4, we got 8 DME tags. All 8 had my name on them. Two had my name twice, two had my name and my wife's name, etc. Just be sure that 2 of your 4 tags don't have both your name AND someone else's name. If that's the case, "you" will only be able to use the 2 that have ONLY your name on them.