Well - if “royal flush” means just good enough that something successfully reproduces and its offspring survive to reproduce more … and what does “rarely” mean? Over some “possibility spaces”, “rarely” might mean that something happens quite often. But I realize that this is just begging the question and that all these are ill defined terms. A poker (or any game) analogy can probably only be pressed so far.
Your point is well-taken that stepping up through successively more valuable poker hands is going to be problematic at some points. But that just shows the weakness of our chosen analogy and doesn’t reflect on real-life evolutionary drift.
The way we set this up - maybe so - I’ll even concede it without flushing it out any more (so-to-speak). But while we are still attached to our project here I would also note that evolution probably does not need “royal flushes” every time (and certainly not suddenly from scratch). That would sound more like a caricature from creationists who labor under the misconception that intricately functioning systems as we now see them had to “spring up” at once from an a-biotic muck, or fall together at once from a vastly more primitive system before it. That still ends up being more like the microscopic version of the “hopeful monster” caricature of evolution.
I know this is off topic for this thread. But if we want to persist in this and deem it worth it, we can certainly make it the start of a new one.