This.
While our datafiles may seem "official" in the way they are presented/written, some specifics on things may or may not be based on the situation of the story, rather than official source numbers.
Unfortunately, a lot of information from "official" sources are just as much guess work based on other information from other sources or their appearances. IE we can guess how strong Powered Zerebubuth is based on info from normal Zerebubuth. It may not be 100% accurate, but it's likely the closest safe bet.
So when we introduced him to our fanfiction ( long before the book/DF translations), we likely assumed that he got an overall power up across the board. And technically, we aren't incorrect, though the newest source material does not state anything about physical power, so the design may have just got new weapons.
Even the "strength of 15 men" is almost irrelevant in terms of measurement until we are given a baseline for what Chronos considers "the strength of 1 man"