In a world where special hero characters can be 3D-printed easily enough by anyone with the hardware, I almost think I'd rather dedicate the resources to more weapon/gear options to dress up the rank-and-file troops with, and then sell heroes separately via Atalantic Digital STLs or Only Games printed sets.
And with a wealth of D&D fantasy minis out there, plus offerings from the likes of Frostgrave (Wizards, Knights, etc.), it's extremely easy to find wizards and such to complete a fantasy army with, if you're willing to go third-party. Reaper's got tons of Bones plastic wizards and warchiefs of every description, for example, and really those RPG adventurers are the very stuff of hero characters, no?
That said, I think that in theory a hero characer on a sprue with four or five rank-and-file troops COULD be done well in some situations, where the hero character's body could still be used as one of the regular troops - the weapons/hand poses, heads, and other extra bits and bobs can make most of the difference, I think, in these situations. This might especially work, if by "hero character", you mean something a little broader than a leader: characters who might be doing or equipped for something a little different from the other troops; in more modern or sci-fi armies, this might include medics, radio-men, heavy weapons guys... and again, it's situations like that where it's the heads, arms, and add-on gear make much of the difference. In fantasy terms, the difference between a "hero character" and other troops might simply be a little more or a little less armor, and as long as the "hero" body can double for a ham-and-egger body for a trooper who happens to have slightly heaver or lighter armor, then so be it - and yet again, heads and arms/weapons make much of the difference! Probably not the best way to add in a charismatic warlord, wizard, cult leader, or whatever, but I suppose it can be done.
And, I think there are situations where a special command sprue is attractive, though I almost think these sorts of sprues might almost be best filled out with some sort of equivalent to the Frostgrave Wizards or Knights kits: a large sprue for four or five very colourful "heroes", with a huge variety of eccentric and specialized heads, arms, and other gear, and then sell these sprues not just as singles in the box, but maybe also separately on the site specifically for RPG or small warband "hero"-building purposes. At which point, you might almost be better off selling separate hero kits, depending on how the economics work....
I also think it might be do-able for WGA to make a boxed set of generic one-size-fits-most "hero" bits that can be used to make special characters for a variety of different armies - after all, you can get a lot of mileage for avariety of fantasy human and elf (and even historical) armies (for example) with a sprue that contains, among other things, bodies in ornate armor, heads wearing crowns, bodies in elaborate robes that could work for clerics, necromancers, wizards and cult leaders, capes, pointing arms, arms holding spellbooks/holy-books, hands with standards, arms pointing swords, and so on: many ofthese sorts of things can be used for non-human armies as well (your orc warband doesn't necessarily need to be led by an orc, an evil wizard or corrupt warlord often works just as well, and a hooded-and-robed wizard/cultist/necromancer type character can pretty easily lead an army of undead, especially if some of the hooded head options are hooded skulls and the robe arm optons include skeletal hands..... Its use beyond human and elf characters might start getting a bit unweildy, so dwarf and halfling gamers might be at a bit of a disadvantage, but maybe with a generic leader-for-(almost)-any-occasion boxed set with two or three different sprues could even make some token nods at non-human armies by including a few heads and arms or even bodies for hafling, dwarf, orc, goblin, or other non-human heroes, depending on how far the economics will go....
All in all, though, I'm really thinking that WGA might get the most bang for their product development and manufacturing buck, and their mass wargaming customers' buck, simply by aiming at the ham-and-egger troops for boxed sets, and then designing nice hero characters for digital sales....
Which seems to be kind of what WGA was experimenting with, in characters like this Irish Chieftain, and Vlad the Impaler, either of whom would, incidentally, make fine hero characters for fantasy armies:
I think the main trick in this, would be accessibility for those of us who haven't dipped our toes into home printing yet!
Still, for those of us who can't print the heroes, and where Only Games or other third-party printers cannot fill the printing gaps as middle-men, there's always the options mentioned by others: painting a leader slightly differently, using the usual "hero bits" like standards and pointing fingers and capes to stand out, and kitbashing unique bits for them. Or, just buying third-party RPG character minis. Theseare not exciting solutions for all gamers, but they're always available to fall back on and easy to work with!
