Esperanto has a funny word for leader

The picture is from like page 2 (or "page 4") of chapter 2 of the Esperanto translation of Sailor Moon on Mangadex.

Esperanto estro ("leader") is from the productive suffix -estro ("leader of..."), itself from Italian maestro ("master").

I'm frankly curious how much of a coincidence this really is, though. I can rule out the "es" parts in estrogen and maestro being cognate, but I don't know about the "tro": in maestro the "tro" traces to PIE -teros (forms contrastive adjectives), whereas in estrogen the "tro" traces to...... Well, no online etymological dictionaries want to say! So it seems possible but not super likely to be from that same PIE suffix.

The word estro also shows up in Italian, Portuguese and Spanish as a regular reflex of Latin oestrus, and interestingly enough Wiktionary also tells me that estro is a word in Galician meaning "oven floor" or "animal bedding", cognate to English stratum.