Thanks for dropping in. This advice from Tariq of one guard per app/use case supersedes the current conventional wisdom of one guard for everything. It compartmentalizes your activity so even if you were to have a bad guard only part of what you do is exposed while the downside of using more more guards minimally raises the risk of exposure.
Tor’s “default” is of little relevance here since it has no concept of virtualization or different apps. This is an overlay and a product of the way we use it in Whonix.
No let me explain below
No You use 5 different guards only because it’s the number of apps we care about. So five different snapshots of the Gateway started from a pristine condition.
The only time you’d use separate GWs is when you want to multitask and run two activities at the same time rather than firing up a single snapshot *say for email first) doing your thing then restarting the next one for Mumble for example.