Yes current consumption is current consumption. The adapters do send more than the cameras need, but the cameras will only take what they need from that. V3s take like a third of an amp, maybe upwards of 0.6A at most. So you can probably power 2 V3s from a standard 1A adapter. But maybe 3, if they aren’t all running everything at the same time, lol. I would also agree that to power 3 you should have greater than a 1A adapter, which would be at least 2A.
You could also consider using “Low Voltage Wiring” and burying the wire from an A.C. power outlet (indoors) power supply to the cameras. Then use a 12 volt to 5 volt micro-USB regulator adapter and install to camera.
The power Supply mounts indoors but the cable to camera can be longer as the 5 volts is regulated at the camera.
I have ran over 180 feet of 2 conductor cable to camera with this setup, use low voltage lighting wiring it can be buried, it is weatherproof and UV resistant.
Connect the 12v to 5v micro-USB regulator adapter to cable matching polarity ( +red -black ) along cable where a camera is needed if more than 1 camera just get a 12 volt adapter with more current (Amps) The Adapter regulator is weatherproof except the micro-USB itself but the boot on the V3 takes care of that.
Links below to several power supplies, 1 Amp for 1 camera, 2 Amp for 2 cameras, or 5 amp for 5 cameras,
choose according to your needs. The cable run can have multiple connections for cameras along cable.
This location originally had a V2 in an enclosure, the 12v to 5v adapter has been exposed to rain, snow, and heat of summer for over 3 years. Recently replaced V2 with a V3
Below is an event captured by this camera, note I don’t use IR as I get too many flying bug triggers.