What is the best marauder to attack for hero development and courage medals?

I usually attack the one that gives the resources I need most since the points you receive is based on level and not type. In "Zone Comm." research just past 50% you can research to get 100% more points for marauders... that stacks with your CoP boosts and those 2 alone give you 600k for a lvl 15 mob. Also other factors and multipiers in research will effect your points so that total will be higher. I would not do destroyers for points just do due the stamina costs being double. Also armor can save you on stamina when attacking marauders, which allows for more attacks and points.