Bristol Britannia/Canadair CL-44 Yukon maintenance

I typically try to stick to aircraft families to keep maintenance costs down. I noticed just now that the Bristol Britannia and Canadair CL-44 Yukon show up in maintenance expenses as TWO separate families (with identical $1.25 mil/month base costs) but both labeled Britannia. Should they be one family? Or should the two families have more distinct names? Hoping for the former, especially since Vickers Viscount and Vanguard are very different aircraft but still appear in one family.