It is an effort that may or may not be profitable. It would extend a lot of "good will" and be in the nature of an investment. I'd go with Print On Demand with a stiff markup, so that if you want to run those five Shermans you have to buy five Sherman cards from FFG. The rules would probably have to be made up just once and could even be done as "official experimental" rules. Several people have noted that some easy tank rules are:
- Tanks have to expend a MOVE action to change facing, otherwise they can only MOVE ahead.
- Tanks need to have facings so they can be attacked vs different armor values.
- Tanks may be MOVE2 by default and/or may gain a bonus to shooting when stationary for being a more stable platform.
Give them a FFG stamp of "official test rules" and people will play with them, test them and give the data back to FFG. Now the bulk of the effort falls on the fans, not FFG.
Extending good will can be very nice, but good will that requires company resources for development can be very expensive. Any unit will require company people for development and playtesting. Pre-release fan playtesting can find issues, but frequently is lacking in competence as the playtesters are more interested in playing with new shinies than in verifying game balance. That's why so many games wind up with problems when new units are released. Developing any new units takes company time and resources. FFG is a growing company, but they also have a lot of commitments to continue with other games. They only have so much in resources for develoment of any game, or their other games will suffer.
Tank rules would only have to be made up once, but every hour of company time used to create and balance those units along with images for cards is expense and resources that could instead be used to develop the Soviets, Japanese, and other units. Which is more important? I'm a historical WW2 gamer, with lots of historical figures I could use for biger DUST games. I'd prefer to see the Soviets, Japanese, and more Allied and Axis units, even though I'd like to see historical and VK tech vehicles, as well.
As for tank rules that have been suggested, consider these points:
1) Tank maneuver I think is a nice idea, as tanks do traditionally have issues changing direction. That's why turrets were developed. How much that impacts with the facing rules for DUST Warfare, however, we don't know.
2) Tank facings can be very nice, and the historical games I prefer do deal with varied armor, but walkers are likely to have varied armor, yet DUST gives them a base value for all facings. Armor is varied to improve performance, and walkers would worry about that just like regular vehicles would. If walkers don't worry about armor facings in DUST, it's likely that tanks shouldn't either. I could see a future development of something like 'DUST Warfare: Tactical' that enumerated armor values for different target points for walkers and other vehicles, but the game currently does not run with that much detail. With that detail slowing down game play, and DUST still working as a good tactical game with single armor values, there isn't much need.
3) Tanks do not need to be faster than infantry at the battlefield level. Cross country performance for tanks reduces their maximum speed, and visibility while buttoned up for combat, even with an exposed crewman on a pintle mount, can keep them even slower. I would expect a walker at full speed on the move could go much faster than an infantryman, or they would not be as useful for modern warfare, yet DUST acknowledges the battlefield for them, and dropped their speed. Blitzkrieg works on the speed of units on the breakthrough, but tactical speed moving up to the breakthrough has to be much slower than a vehicle's maximum to attack with maximum efficiency. A stationary tank is a much more stable platform than a moving tank, or a moving walker, but would not necessarily be any better than a stationary walker. Since stationary walkers get no bonus to combat other than the ability to use Sustained Attack, there is little justification for giving a vehicle a different bonus for being stationary. I could see a penalty for some vehicles firing while moving (those with no stabilization), but that would require more resources to verify what vehicles should qualify. Since VK technology would be added to existing vehicles as possible, there is a good rationale for not applying penalties for vehicles, and thus also avoiding the development expense of coming up with point cost changes for vehicle disadvantages.
Anything FFG puts out for DUST has an inherent stamp of approval, so I can understand them being slow to add additional material without first doing internal work on it. As I noted, fan playtesting can give important data, which is why companies use it, but that data is frequently tainted, and has to be verified in house if FFG wants to maintain correct competitive balance. I've seen too many companies through the years that screwed up their games when adding expanded rules because playtesters didn't do their jobs, and the company didn't verify the playtest data.
Bad units or rules, even if released for 'unofficial' units, can generate a lot of 'negative will,' that could do more damage than the good will generated by adding traditional vehicles.
As I've said, I'd love to see historical vehicles added to DUST, but there are other things I see as more important. There are players who want historical units, but others that don't. There are few players, however, who have no interest in the Soviets and more walkers. If I were FFG, I know where I would be using my development resources.