Honestly, skip the worry about the preamps! I used the Rode VideoMic NTG Shotgun Microphone on my a6400 for months and the audio quality is just insane. It sounds super crisp! If you want something tiny that stays out of the way for vlogging, the Sony ECM-G1 Shotgun Microphone is also fantastic. I absolutely love how portable it feels. You really can't go wrong with either, but the NTG is a total game changer.

^ This. Also, honestly, the internal preamps are just noisy garbage on those bodies. I had issues with the signal-to-noise ratio constantly when using shotguns. You should really just grab the DJI Mic 2 1-Person Kit instead. It bypasses the camera audio chain entirely by recording internally, saving you so much headache in post. It is way more reliable than dealing with that messy ZV-E10 gain staging.

Regarding what #1 said about skipping the worry, be careful with those internal gain stages. The preamps on the a6400 series can introduce a bit of hiss if you crank them too high. I would suggest looking at wireless options from brands like DJI or Rode instead of just shotguns. Just get any quality digital wireless system, you really cant go wrong with those for vlogging since they bypass the camera noise floor entirely.