Your skin is not uniformly dry, so treating all of it with one product is why some areas never catch up.
Forearms and shins usually do fine on a daily moisturizer. Knuckles, elbows and heels are often weeks behind and need something else on top. The three formats below are not competing with each other. They do different jobs.
Lotion: the everywhere, every day option
Lightest of the three. Absorbs fast, spreads far, does not stop you getting dressed. This is the format you use on most of your body most of the time.
Reach for it when: you want head-to-toe coverage, twice a day, without thinking about it. An extra dry lotion is a step up in richness while still being spreadable, which suits larger areas that need more than the daily product.
Balm: for the small areas that stay bad
Thick, occlusive, slow to absorb. All the things that make it wrong for your whole body make it right for knuckles, elbows, heels and fingertips.
Reach for it when: a specific patch is not responding to lotion, or you need something to stay put overnight. Use it on top of your daily moisturizer, not instead of it. A little goes a long way, and applying it before bed avoids the greasy-hands problem entirely.
Oil: for the areas that need feeding, not sealing
Oil sits between the two. Lighter than a balm, richer than a lotion, and it sinks in rather than forming a layer on top.
Reach for it when: skin feels tight and papery rather than cracked and rough, or on areas you do not want to feel coated. A few drops warmed between the palms goes further than you expect.
The rule that makes this simple
Lightest first, richest last, and richest only where you need it.
Lotion over most of you. Oil where skin feels tight. Balm on the two or three spots that are genuinely worse than everywhere else. If you apply a balm before a lotion, the lotion never gets in.
What this looks like in practice
Daily and all over: the Eczema Nourish Moisturizer, or the Extra Dry Lotion for larger areas that need more.
Targeted and rich: the Extreme Balm.
In between: the Probiotic Moisturizing Oil.
The richer two live in Nourish, which is step three of the routine. The daily one lives in Hydrate.