Oh come on - very few aeroplanes use skids any more, and that really is a type specific issue. Hard versus grass, yes - and also crosswinds, both 2 and 3 point landings, and whatever else is peculiar to the particular type. But expecting a new tailwheel pilot to be able to handle every possible variation is equivalent to expecting someone learning to land a PA28 to also handle an AA5 castoring nosewheel "just in case". There is a point where specific features should be left until someone may be checked out on a specific type.
G