I like your idea Martinus very much. The more customization options the better.
This [Another way of earning cards](
http://warlight.uservoice.com/forums/77051-warlight-features/suggestions/1366941-another-way-of-earning-cards?ref=title) UserVoice idea gives players/teams not only the opportunity to get different cards but also the ability to fight for them, giving additional depth to already brilliant game .
I am going to try to promote this idea right after successful implementation of this one : [Multi-attack card] (
http://warlight.uservoice.com/forums/77051-warlight-features/suggestions/1358929-multi-attack-card?ref=title)
fingers crossed :-)