I’m sure Toei has realistic expectations with these movies. Based on how Season 3 sold in Japan, as well as their relaxed timeframe to complete them, they know exactly what to expect.
The movies & Crystal are an attempt to keep the brand out there so that they can keep targeting their new audience- nostalgic adults. If the movies were their main source of income, then they’d fixate on numbers. But they aren’t pushing them to the same audience of the 90s, or even PGSM.
Sailor Moon just isn’t the big juggernaut it was in the 90s anymore. It’s no longer aimed at kids- they would be churning out dolls and toys if that were still the case. They’d be in toy stores. Instead we get niche fashion aimed at nostalgic women and collector toys.
Essentially, Sailor Moon is a legacy brand like Hello Kitty or Mickey Mouse. It doesn’t really matter if the movies/ shows flop, as long as there’s some current media still around so they can keep printing Usagi on shirts, creams, condoms, etc.
And yes, it helps that Sailor Moon is considered iconic to the international anime market. None of the other magical girls have gotten to the same level internationally. And that’s another aspect as to why they’ll keep pushing its content.
Long story short, I wouldn’t worry about numbers.