What defines a skirmish game?

I've just been reading a rather interesting post over on House of Paincakes. The author Cedric is talking about the current proliferation of new games, at least in part driven by Kickstarter. He talks about what happens when you want to try something new but nobody else does. What do you do? Abandon the idea? Do two (or more) factions yourself?

Often the cost of a single faction for any given system can be the most an individual can afford, leading to a number of commentators suggesting playing skirmish games like SAGA, as the cost of entry is lower.

And that brings me to my point. What defines a "skirmish" as opposed to a "wargame"?

Wikipedia defines skirmish games this way.

For myself, I'd suggest that the generally accepted view is that skirmish games are where:

1. the number of figures required is substantially lower
   and
2. (as a consequence) the cost of entry is lower
   and
3. the figure scale is typically 1:1 - individual figures are "units"
   and
4. (as a consequence) the level of characterisation is substantially higher

The interesting thing for me was that Cedric's opening put these types of games almost in opposition to GW's various Warhammer flavours (hereafter "Warhammers").

To me, the Warhammers ARE skirmish games and here's why:

1. figures are based individually
   and
2. there are lot of characters who act individually
   and
3. the figure scale is 1:1
   and
4. an "army" in reality consists for a couple of hundred models (at the extreme)

BUT conflictingly (at least for Warhammers):

1. there is a high level of characterisation
   and
2. the cost of entry is anything but low

So are Warhammers skirmish games? If not, what are they? And if they ARE skirmish games, what does that make SAGA (or anything else of that size)? They may well both BE skirmish games but it means that you're defining "skirmishes" in very broad terms...

OK, semantic rant over ;-)

Have I missed something blindingly obvious? Comments? Thoughts?

Cheers,
Millsy