How to effectively use Crocodiles and other flamethrower units?

[All_American]

I've been playing some of the scenarios that take place around Caen from the British side recently. I've came to notice that Crocodiles don't have a strong soft attack value as I first imagined, but they seemingly have an abnormally strong assault value. My question is, how to utilize this in the best way possible? Do I use these assets as bunker busters, as in assaulting the defenders without disrupting first, or assaulting entrenched infantry but not against bunkers? Any tips are appreciated.