Of course I don't know what the optimal size is. Yet, to be competitive in terms of speed, range, and payload, "small fighter jet" sounds about right to me. At

Of course I don't know what the optimal size is. Yet, to be competitive in terms of speed, range, and payload, "small fighter jet" sounds about right to me. At least, if you want to convincingly fill most of the roles that manned aircraft fill in a conventional carrier strike group. That'd include not only things like reconnaissance and weather observation, but also air-to-air and air-to-surface missions over sea and land. So, a kind of hierarchical scheme where the carrier deploys the big drones, which close onto the target before deploying the secondary, disposable missiles/drones. You want to be able to stand off any opposition forces well away from your naval group.