There are no numbers, it's your body and how it responds to the food you give it. Some people can have pasta, I can't.
For me, I started where I was at goal and X'd by 10 to get a 'starting' calorie count (but that's just an idea I found on 3FC's in the maintenance forum(s)). HOWEVER, I naturally follow the rules of Phase 4 by keeping fats and carbs separate. I think some maintainers have collected their numbers based on their bodies, ie, I know I'm naturally low cal because I track my food and I am good anywhere between 135-170 carbs a day...it all evens out in the wash.
When it comes to making a choice....FOR ME...if they are equal in carbs and fats then it's probably not a good choice as they aren't following the rule of keeping fats and carbs separate. HOWEVER, that's just me and I'm really just a newbie maintainer!
I do VERY MUCH so, keep the refined sugar OUT, I still use stevia and splenda (limited quantities) and I do keep my protein count a little higher. Ie, an evening snack is fruit and greek yogurt (plain, fat free sweetened with splenda syrup).
Maybe some others might jump in.
IP doesn't give you "#'s" because it can't...every one is different. Phase 1 everyone can lose weight on....Phase 4 if you handed me some 'rules' and you some 'rules', they wouldn't apply the same way as we have different bodies and we assimilate our food differently. (I can have potatoes….some people can’t)
It's all about making sure you take the time to listen to your body and how it complains.
Sorry, you probably wanted more...do you have a coach?