Failback sites - Sites with priority

Hello!
As I have mentioned it before, I have two sites with channel data, the first one has more information but it is not updated regularly, the second one is updated but has less data... I think it would be easy to implement support for priorites, or failback sites:
For example, when a site has no index shows for a channel (or even maybe a day is missing - OK, maybe per day is far fetched and more difficult, but anyway...), the program would try to get the data from another site, which has a channel with the same id.
It happens a lot here, especially now in August! ;-)
Please consider it, I think it is easy, because for now what I am doing is having 2 config files I interchange when I see gaps in my EPG! :-/