A scientific theory is often said to be an explanation. But that's a mistake. It's on the basis of that mistake that creationists want to say that creationism is a science.
I don't think it's necessarilly bad characterisation to call science "explanation". As long as the "explanation" makes sense. And explanations only make sense when they use and combine known and well-understood facts and processes. Because obviously you can only understand an explanation if you understand the concepts that are used in it. The explained phenomenon can then become a building block itself, within future explanations.
In that sense, being an "explanation" also automatically leads to the unification you mention. It gets embedded into the total body of knowledge.
Creationist "explanations" are severely lacking in that respect. They tend to be "ad hoc" and as such they don't really offer any useful integration with existing knowledge. This lack of integration then leads to a lack of verification. There are so few dependencies that it is destined to remain shaky "knowledge".
Let's also not forget that since the answer "God" fits all questions, it could just as well not fit any at all. An answer to everything is an answer to nothing.