How this could work is the maps with conquest mode would have an alternate xml file for conquest mode. Conquest mode would then be enabled with a check box, which would tell the site to use the alternate xml file. The reason it should be implemented as a checkbox is because it can coexist with all other game types. (I think it would be especially great for assassin games)
Priority 1 (Low)
Some examples of maps that seem compatible with this new game type and how it might be implemented on them:


Here I use ugly orange S symbols to designate possible start locations:

