So the better answer is that it is "threat dependent".
And as long as our adversaries are armed with sharpened mangoes, then we are ok.
At some point.....professionalism, stout hearts, and good kit are all trumped by numbers are they not?
'Quantity' has a quality all its own. We are probably now too small to take on the 3rd Guards Tank Army (except in a minor, niche capability, kind of way with Uncle Sam picking up the remainder) but can probably manage the PSO in Trashcanistan as an enduring commitment. As long as we are out of AFG first.
And the Paddies don't kick off, cos we are bit short of enablers to cover 2 theatres. Which is probably the more important discussion: do we have enough of the non-sexy stuff to ensure that the sexy stuff CAN support whoever CJO has been told that HMT can afford to deploy? No comms, no bombs! etc.