So, with the caveat that things will become far more ad-hoc in practice even before the actual battles start, it's interesting to see different proposed military organizations. The American Pentomic Divisions are infamous, but the Soviets, at least according to this declassified CIA analysis had a similar "lots of companies to a regiment" proposal they considered, with a similar justification of survival against nukes. It was extremely tank-heavy, not surprisingly since it was a tank academy conference that proposed it.
And there's bound to be others.
And there's bound to be others.