I do not think so. In the case the device craps out so bad that it deactivates the software watchdog, your mission will still be toasted 
Here's another reading you can do:
https://github.com/particle-iot/app-notes/tree/master/AN023-Watchdog-Timers
Lastly, @Rftop you always recommend a cheap timer for an external watchdog and I swear I ran a search and could not find the posts.
Can you tell me which one it is, please? Thanks!