So Purgy wurgy raised a good point over at Best Overall. Let's assume Games Workshop is going to release things like Venoms, Tervigons, Tyrannofexes, Thunderwolves, Harpies, etc. at some point. One imagines they will because there is a huge untapped market of sales there (admittedly diminished by everyone's conversions). The point that Purgwurgy raised revolves around model sizes. Most people have made conversions based upon the army they are using. For example, most Tervigons, Tyrannofexes and Harpies are based off of Hive Tyrant or Carnifex models. If Games Workshop ends up making these kits end up being say 33% bigger than the plastic Carnifex, does this invalidate the conversions of individuals who have based their conversions on what Games Workshop had available at the time?
What about Thunderwolves? Not everyone has converted them so they can be seen when they are behind Rhino chassis but are still based off Space Marine proportions. If Games Workshop releases a Thunderwolf model which is clearly larger than a Rhino (height-wise), are all conversions invalidated if they are smaller? What about Venoms which are generally based off of Raider or Vyper models?
So the discussion boils down to: when do conversions model sizes become an issue, particularly when actual kits are released after the fact? Personally, as long as it is based upon an appropriate size (i.e. the examples listed above), it's okay in my book. Demanding players essentially bin all of their conversions and drop a lot of money on new kits to be technically legal is pushing the friendship, particularly since Games Workshop has taken so long to release certain models (Tyranids and Thunderwolves wave). As long as a player is clearly not aiming to make a much smaller model to gain some sort of advantage of the tabletop, let them go for it.
This also raises the issue of older models. 2nd ed models and a lot of 3rd ed models were a lot smaller than their current counter-parts (we all remember the old Tyrant and Screamer Killer? Land Raider? Rhino?). Games Workshop has no problem with people using these models as they are actually produced by them. Are conversions based off their models any different when they haven't released an actual kit?
Anyway, discuss away.
