Problems in defeating a camp :(

Hi there! I have tried twice to defeat a medium camp, but I have killed only 10 guard dogs! :( Could someone help me infinding a good enough strategy?
I have to beat the following units:
1Boss (9000)
40 guard dogs
49 rangers
100 roughnecks

Thanx in advance! ;P

1: 115C 2: 85R 40M 75B 3: 200R (225R 40M 75B 115C) ] (Wave 3: 175R minimal)

Get your help from this thread: forum.thesettlersonline.com/threads/15383-Guide-Combat-Guide-amp-FAQ

Thank you :)