I'm scheduled on a short-haul flight in a few days and was checking flight punctuality, and noticed that the equipment for the past week and the upcoming week (per FR24) varied/varies quite a bit. Was the same Bombardier CS300 (or so it is noted rather than 223 ) for 3 straight days, then a ASL 738 for a day, then E190s for 3 days + next 2 days, 223 (or BCS3) for 2 days, E190 again for 2 days, then 223 for a day before going to E190 (no published data beyond). A few days later, it's scheduled for a 320 and it appears only 2 flights for that particular flight number are operated a 320 series a/c for the whole month of October, alternating between E190s and 223s otherwise. I can see a change from A320 to 321, 319 and even 318 but between different family (or makes) of a/c? The other mid-morning flight does switch between 320s and 223s.

I do see there is a luxury cruise ship leaving from Fusina one of the days the 320 is scheduled and wonder if that could be a factor. 8 rows in BC pencilled in with 7 free.
r

Short and medium haul flights are subject to a lot of changes, that's normal. It depends on the route but frequently the same flight will alternate even day-to-day. And then you have last minute changes due to tech, crew, and scheduling factors. That's part of the reason Euro-business is the way it is, they can move the curtain until around H-72 without much impact.