It's also why a lot of the 'let's buy this bit of kit' discussions aren't always very useful, as there would be no one to man the extra kit.
totally agree, though some equipment acquisitions actually result in lower manpower requirements even while increasing capability. The flip side of course is that high tech equipment requires a higher percentage of skilled and experienced operators and maintainers, who take longer and are harder to train, then are more attractive to civilian employers.
The above is more the case with the RAN than the Army, or even the RAAF, but would have an impact on the enabling side of the equation. As I understand it CAV has lower manpower requirements than Infantry, even when they have their scouts (assault troops in my day) while Armoured/Tanks have lower manpower again. I could be wrong but I believe SPG batteries require fewer personnel than towed, while the new M-777, still provides a manpower saving over the M-198.
It is a catch 22 in that successive governments choose to apply manpower caps while also failing to invest in the sort of capabilities that would mitigate the cap. I also understand that part of the issue is the government choose (or at least used) to include personnel under training under the manpower caps. This used to be the case on submarines where ships staff who were not yet qualified in their nominated roles, let alone effective, were counted against the totals causing much extra work and stress for the qualified senior sailors, hence higher separation rates. I can imagine similar happens in the army though I doubt not being able to replace a single qualified technician could prevent an army unit being deployed.