There are basically 2 ways to sponsor. If the file is processed in the spouses home country, it is usually faster to get PR. This is called an outland application. If the file is processed completely in Canada, the spouse must already be in Canada and not adviced to leave while the file is being processed. This is called an inland application.
Which application a couple chooses can depend on their situation. If the spouse needs to be able to travel out of Canada while they are being processed it's better to do outland. If they come from a country where outland is slow anyway but they are already in Canada and don't need to travel, they might choose inland.
Both of them not living in Canada is basically just a twist to an outland application and takes the same amount of time. The only thing that is different is that they need to prove to Canada immigration that they are planning to live in Canada after the PR is granted. This only works when the sponsor is a citizen, not if it's a PR.