A lot of people feel it's nitpicking to ask people to actually put a bit of effort into their 30k armies. I can understand this, but we (or I, I suppose) aren't being a rivet counter, what I'll let slide is a pretty long list, I just ask that someone applies some of the same level of effort to building a 30k army that I did. I think no 30k player is going to ask you to have a fully Forge World army, by the same token, if you don't have the funds to do so, nobody is going to exclude you if you use your 40k army. As I said in the video, a stopgap measure, such as using your 40k minis because you can't afford 30k, is fine! The line is basically drawn at people who have the capacity to build a 30k army, the funds to do so, but refuse to out of sheer laziness. Lastly, apply this logic to other games. If someone bought a Space Marine army to Age of Sigmar, some eyebrows would raise. If someone had an M1A1 Abrams mixed in with their Shermans in Bolt Action, I'd have questions. You use the right model for the right game, and it's not elitist IMO to expect people to put that tiny little bit of effort in, and this is the key phrase *where able*.
I mean Mk7 came out during siege of terra but the only army with the excuse to have it are Blood Angels, Imperial fists, and space wolves for a 30k army.