Herrmann is only debatably the best skier in biathlon. On her day she's peerless, but Eckhoff and Røiseland have both been as good or better several times during the season. Using the ski speed guide from biathlon.com.ua, Eckhoff and Herrmann are pretty consistently in line with one another. It's a flawed metric, but according to their calculations, Røiseland has been fastest this season (where did her ski speed come from in late 2015-16?), with Herrmann and Eckhoff tied for 2nd. They were also tied for 4th/5th in 2017-18, with Herrmann being slightly quicker than Eckhoff last season. There's then a bit of a drop off to Mäkäräinen (who is now retiring of course) and Braisaz, then a smaller one to Aymonier, and then another one to the likes of Wierer, Tandrevold and Öberg. Davidová fits into that group as well, but on her day she can be up there with the Braisaz types, but she's just too inconsistent. Likewise people like Häcki and Mironova were setting top 5-10 ski times in December but fell away massively in Jan/Feb.
You would expect given the relative perception of their talents as XC skiers that Stina would comfortably slot in ahead of Marte, sure, but there's also a couple of factors to take into account. Firstly, Stina has missed almost an entire season due to injury, and so will she immediately get back to the kind of level that she was at? And secondly, just how much time is she likely to lose in the range? It's all well and good skiing among the best, but if you shoot really slowly, it can hold you back - just ask Justine Braisaz, who once podiumed a race with something absurd like the 92nd best range time that she'd have comfortably won otherwise. Pacing one's skiing around the shooting is another factor that Stina will need to learn, easing up toward the end of the lap, that took Herrmann some time although she started out on the IBU Cup where it really didn't matter too much. I don't have much concern for her with regards to getting used to skiing with the rifle on her back, as she's got a fairly smooth technique when she's not in sprint mode and, being quite tall and not the rail thin Mäkäräinen type, the additional weight won't be as much of a factor to consider. I suspect she's quite similar in height/weight to Hanna Öberg, but I can't find any stats right now to confirm.
Bavarian - even without Stina, Swedish women's XC looks pretty healthy right now, with Frida, Ebba, Jonna Sundling, Linn Svahn, Maja Dahlqvist, Emma Ribom all coming through. They don't want for talent atm.