This is very hard to answer without having the lenses because most of the modern lenses reduce their focal length when focusing up close
(even modern fixed focal macro lenses like the micro-Nikkor 105/2.8 VR do "it")
At least one thing I can say: 20cm distance from the sensor to the subject is short enough to generate 1:4.1 magnification even if the "real" focal length of the zoom shrinls to 32mm. So I would say "yes", it's entirely plausible.
As to the 40-150 with a closest focus distance of 143cm: a magnification of 1:8 could be reached with only a shrink to 141mm. So this also looks plausible.
But again: the shrink-factor of each modern zoom depends on many factors and can only be estimated from the external data.
Thomas (beware: Nikon-fanboy and moderator!) My Lens Reviews
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