2. Clouds: face east, NW and SW (yellow arrows). Sludge: face east (blue arrow)
With lower stats you should start at a lower wave, ie. wave 18. Have a Tboost monk and an upgrade adept. Add in a summoner with App and Hunt guardians, and also add in the warden builder for extra punch. Tower boost from start to around 1.500'ish mobs in. Reset the Tboost and click it back on ASAP. At later waves the combo of wyverns and djinns can be overwhealming. Consider using the wardens wrath ability for that short phase (starts around 2.200 mobs to 2.550'ish).