What would that mean? Are miners then mining LTC and DGB simultaneously?
When you mine you would be mining Dogecoins & DigiBytes at the same time.
This sounds quite interesting from a miners perspective. However, what are the experiences at Namecoin?
I fear this would push DGB in Litecoins shadow for all time.
If this is just to prevent forks, you should take a look at the CGA thread. There is someone working on a anti-forking feature which pushes mislead clients back to the right one. I don't know any details though.