Oh… please don’t be too enthusiastic about his one. ṃ and ṁ are not different sounds, they are just variants in spelling and mean exactly the same. Some scholars prefer one way, some the other. On SC you can toggle between the two by typing ALT+M, see Easter Egg 🥚 1 
I simply use ṁ because I have an easy keyboard shortcut for that one. 
And please compare the “saṁghe” in your first voice example to the “saghe”, “saṁghe”, and “saṅghe” in the second—there’s a clear difference! I mean in the previous example I still can’t detect any “ng” sound at all while in all the latter examples there is one (slightly different for each), even in “saghe”. So I’m not sure what Aditi is doing here… 