The Ukraine experience emphasises the importance of big munitions stockpiles.
I guess if you have to fight the likes of the Russians the Russian way. I'll wager NATO's 'modern' way of fighting, with emphasis of air power, stand-off, combined ops etc etc is still the way to go.
I do wonder why we even bother to field any armed forces other than nukes as a last resort insurance policy plus maybe a handful of warships and fighters to patrol our territorial waters & airspace. I mean, what are the odds we would ever be required to take on Russia (especially now, given their forces have been shown to be a wafer-thin paper tiger) or China over Taiwan? We'd be a bit-part player in the latter at best.
Personally I think our defence budget would be best donated in part to the likes of Poland & the Baltic states, with the proviso that they spend it on UK manufactured kit....