miiro and pika girl are the definition of overranked
you didn't mention either so you obvioously can't be overranked el em ay oh
The pp gain system, while people complain for days on months about how inaccurate is, happens to be precisely accurate when it comes to base concepts such as speed, OD, note density, etc. In fact, let's just say for base difficulty, pp gain is 100% accurate.
Now, you deserve any pp you got from any maps in the basic terms. HOWEVER, players higher up in the ranks tend to look more and more towards mods such as HD, HR, and DT. Some of these change base difficulty, others require special skillsets. The truth is that there are many little factors that make up a player's skillset that don't account in base difficulty.
Now, on a player-to-player basis analyzing all parts of their skillsets, it's possible to find many inconsistencies in how ranking placement works. Keep in mind the density of player's pp-play spreads as the play density affects their other pp gains (weighting to the rescue woo).
I play with a good number of 1k-2k players, often beating them at nomod 6+ stars. They're not worse than me necessarily because I know who they are and they'd probably crush me in DT or HR or even JUST HD (on relatively easier maps lol).
When you get into the mid-high ranks (50k+) you begin to realize that a skillset's reliability tends to far outweigh your base abilities and that you may experience huge fluctuations in "how good you are compared to your rank".
However, in peppy's eyes everyone is equal. If pp states that you have earned X amount from your base abilities, then you have earned X rank and deserve to be in X position.
Oh yeah, try to warm up well before multis in case you're the type of person whose ego silently blows up in multis (like me admittedly).