There's a difference between acting quickly on information presented to you (which is more speed of information processing/processing speed as it is usually assessed), and retrieval fluency, in which one needs to access and produce information that one already has stored away. The latter has a lot of EF implications. I've used the messy closet analogy before. It's all in there somewhere, but the filing/organization/retrieval pathway is so inefficient or disorganized that finding it on demand is difficult. Often, cued or recognition recall will be much better than free recall.
I usually recommend that students learn to attach memory "hooks" or personally-meaningful mnemonics to information, so that there will be a "fishing line" attached to a group of related content or skill standards. Or you can think of them as links or beads on a chain/thread. Using mental walk-throughs or narratives can help, too. E.g., you memorize and later retrieve your grocery list by standing in front of the refrigerator (IRL or mentally) and looking at each shelf for the item that you need to buy. Or tell yourself a story that involves all the pertinent steps of a process/skill, with vivid sensory, relational, or emotional (including humorous) cues connecting each step.
This doesn't, honestly, help that much with retrieval fluency, because it's not that fast, but it can be helpful as a compensatory strategy for retrieval weaknesses in general. And I figure it can't hurt for fluency purposes, as it minimally gives one some sense of control over the effort to pull up facts and skills.
