Sure Duncan - I skip a lot of bases when I raid also. You know I actually count and calculate how much I'm spending as I go... that is nerdy, but keeps the brain sharp.
What I'm saying is, that at 900 medals, if you've got L2 walls, you must be attacking people in the 900 medal range... So, are people not doing Revenge? I always check them, and look for chances. Especially guys who have raided me and only got away with a tiny amount - that's generally a good idea they don't have a clue. Guys who raid me for 5 starts usually are high level players, with lots of guns! (me soon - I'm saving for enlightenment, and canon troops)
There's been times when I've been raided for a few thousand, and I've Revenged back for 100k, and medals.
I guess - if people aren't doing a lot of Revenge... and you're raiding a lot, and picking easy targets - sure you could get to 900 medals with L2 walls. But it seems that you're opening yourself up to a lot of risk? Maybe they just want the glory!?!