I believe the Lamb & Apple is a grain-based variety of Acana - but it still has good protien sources but if you haven't been feeding your dogs a grain-based diet in the past just be cautious of their reactions when you go from Acana's grain free (Grasslands, Ranchlands, Wild Prairie & Pacifica) to the Lamb & Apple.
I personally have been including all of Acana's grain-free line in my mix and rotating through the varieties for the last few years with no issues - but I dont feed the grain inclusive so I can't tell you anything about Lamb & Apple.
I'm a big fan of rotation, I also mix 3-4 brands together at once, I"ll stick to a few brands that I like but then I just rotate through their varieties and flavors. But I stick with grain-free, I just recently tried including a grain-based kibble into my grain-free mix and my dogs instantly got itchy dry skin, and Thumper lost hair in some spots. No more grain inclusive foods for my dogs. My current mix is Acana Grasslands, Fromm's Surf & Turf & Nature's Variety Instinct Turkey & Duck. I also use Orijen, NOW! & Timberwolf's grain-free variety. These brands I pretty much stick with in my mix/rotation as my dogs always seem to do great on all of them and the varieties.