That's just not true. Wide spread of model age is the default state in most 40k armies, and it works well enough.
And dead armies don't count.
There must be reasons why they do it the way they do.
I personally disagree. The Skaven faction is an example of really mismatched sculpts. Lizarmen as well.
In 40k the older models stand out like sore thumbs. Khorne Berzekers being a good example. Obviously some factions hold up better then others.
The Orks always done really well in this regard because the basic ork model looks good, and they have a make shift design that's easy to expand on.
But things like Necrons. They would be easy to make new models for, as the Necron look is so standarised. But what happens when the Necron look stars to look outdated?
That's what happened to space marines and terminators. So what are they doing? they introduce a brand new range the primaris that will eventually replace all the old space marines.
Also it makes sense as well. They are trying to sell new miniatures to people. If they update the Saurus, most people are probably not going to bother updating their Saurus. So they will only sell the models to people who start a new army or a few die hard fans of saurus.
It would make more sense, to wait until the Lizardmen models become totally obsolete and then reintroduce a new range. Same as the new Aelves.
They probably don't want to mix in the new models with the crappy old models, as the new elf models are so good, people are going to run out and buy them.
Contrast this with Cities of Sigmar. An army with a huge fan base. It would be the army I would most like to collect for. But no way am I buying those dated and crappy models. If they released a brand new Steam tank, I would still not be interested.
But if they made about a new faction using, with a few new regiments and characters. All brand new. Even if it had a tiny roster. I would want to go and collect them again.
The point I am making is this. They probably get a lot more hype and sales from new factions with all brand new minitures in them.
When they introduce new units to really old factions like the skaven. New players are going to think the new models look awesome and then when they puruse the rest of the skaven range and get an eye full of the Rat Orgres and other dated models in the range they loose all their will to buy them.
I am guessing that GW probably makes most of it's money from selling new armies to exsisting players who want more armies. As people tend to buy thousands of points at once. And then never use them anyway.
Once you got your army already built, you probably are only going to add 1 new thing to it every blue moon. The updates can wait.
