The typical course of action for any paint protection application is to deep clean, strip, and then apply your LSP (last step product).
If you're just topping after a weekly/bi weekly/whatever time frame wash then you don't need to strip, but you should choose products that will perform under those circumstances, that are designed to work with the base protection product. This is extremely important for ceramic coatings, but it still bodes true for regular waxes and sealants.
For example, if you have a ceramic coating on the car, other ceramic based spray coatings/detailers typically perform better on a coating vs a wax or sealant. This isn't a hard rule, but if you want to get the best results for your time invested, its the best course of action. You also need to pay attention to the performance/attributes of the base product. for exmaple (again) is Sonax Polymer Net Shield. It is an extremely hydrophobic spray sealant, and their accompanying Brilliant Shine Detailer is designed it top it and restore/maintain that same hydrophobic performance. The 2 go hand in hand and make up a good base and topper team so to speak.
Sometimes mixing and matching and off label use will yield good results, but I've seen it mostly do the opposite, especially when mixing based chemistry components like ceramic with polymer or wax.
In my experience any mild pure polish followed by a panel wipe/degrease (you can make your own using 99% isopropyl alcohol mix 5:1 with water - 5 parts water, 1 part IPA) will give you a bare base ready to accept any product on top. If you're working with ceramic products, Mothers makes a primer polish called CMX 3 n 1 Polish and coat. It will remove minor swirls and leave behind a base layer that allows ceramic products to bond (I've tested it with various ceramic sprays and high solids ceramic coatings and it worked great).