Based on experience, 6mm anchors are good for almost everything, except when there are really heavy loads. Here you also have 4 of them in the wall, if it is reinforced concrete I would say that easily holds. In my opinion, a small child wouldn’t be able to tip over a Pax anyway. For heavy loads, use 8mm anchors, for swing hooks 12mm.
In concrete it’s of course relatively easy... but two cabinets, for example, must be attached to Ytong walls... I have the Fischer GB in mind... they should perhaps hold a bit better than the Tox Tri or Fischer DuoPower!?
You’re worrying so much about an anti-tip device for a PAX wardrobe? Oh dear... a tiny little plug would be enough, there are hardly any forces acting there...
Well, what forces act there I don’t know, but saying almost none seems bold... once the thing reaches its tipping point, meaning enough weight is hanging on it as leverage (e.g. drawer or cabinet door open and a child hangs on it or something like that), it gets bad. But it wasn’t just about the Pax for me, even though that triggered these considerations, it was generally about how to deal with anchors (plaster thickness, etc.) and what is short vs. long and what is thick vs. thin with an anchor.