The question comes up occasionally and here's a thread with a picture I found from googling...
https://www.dakkadakka.com/dakkaforum/posts/list/709472.page The 1/72 tank will obviously be even smaller than the one in that picture.
In general
40k scales very poorly with historical models because
40k is basically a chibi scale. Fat gun barrels, short vehicles that are wide and tall, human models that are short but chunky. In general very chunky details.
Even if you find one that looks similar size, it usually won't look right next to a
40k model without considerable conversion.