Yeah I redid some scripts on my team for my own usage because our team bash guru maintained them and didn't want anyone to change them. So I did my own versions in python. Sure they were mostly 2x+ as long but they were very easy to read and modify and test. The bash guru finds out and brings it up at a team meeting trying to shame me, but it ended up with my boss asking the team, and they voted on using my scripts in lieu of the older bash scripts as I had written a few unit tests around them and the rest of the team understood them without digging out unix tomes.

I have done something similar, what I really found worked well was to wrap the bash scripts in python to instrument them and if they just operate on data, you can even spawn another command and run them both at the time confirming that the output matches.

Great way to have confidence in a port and provide for a fallback path. Eventually the new code will take over the old code and the old code will wither and die.

It seems like when a bash script gets over say 50 lines or so I start doubting whether something should be a bash script :) . I saw an IRC client written entirely in bash once and it was quite a resource of esoteric bash scripting haha.