I'd suggest you post in this forum, your question touches on a specific issue that only a few members know well (and one in particular follows very closely):
https://www.canadavisa.com/canada-immigration-discussion-board/forums/permanent-residency-obligations.11/
-To be clear, time spent accompanying you would NOT count for citizenship purposes, except in (relatively rare) case that your appointment is a secondment from a Canadian govt institution or some other very specific exceptions. (About which you would likely know already)
-For PR purposes (that is for the residency obligation or RO), possibly a posting would count, but there would be effectively no way for you to know 'in advance'. Typically moving with a spouse would count, but there is a somewhat arcane issue of how IRCC will treat cases when the PR effectively never settled in Canada (which I'm going to assume would be the case for you).
There are some other factual elements of how you two would spend your time in the ensuing years that could affect this; if you both expect to spend 3-6 months a year in Canada it'd probably be a no-brainer. But if only for occasional visit, basically your spouse would have a PR card and then during the validity of that card (five years) would eventually get asked if in compliance with the RO (which on the face of it would appear not, but could claim living with you), and then have to replace the card. It may or may not go easily, and in fact IRCC might decide the time doesn't count.
But again: none of these days would count towards citizenship. So the question also to consider, is this worth it? Apart from a PR card that gives ease of travel to Canada (at least while in compliance with the RO), and to a minor degree in some other countries (eg Mexico), there are not a lot of direct advantages except for ability to move to Canada at a moment's notice. And it probably goes without saying that the relative advantage of this may be quite small depending on what passport he holds.
You could sponsor your spouse when closer to retirement, for example. But you may both wish that he have the PR status already in the event that either or both of you were to lose your positions, or unforeseen circumstances (i.e. morbid ones). It's worth looking into and thinking about. But it's not obvious that you need it. Worth acquainting yourselves with the basics of the RO etc.
Probably clear I'm not trying to put my finger on the scales - it really does depend.
I'm also not addressing the application process and whether you could show intent to return to Canada.