For the record I agree with those who are saying moddability + extensive overhaul DLCs is the way to go for CA. In my opinion it gets rid of the worst of both worlds: 1) no more limitations on the fan-base's imagination 2) no more stupid 3$ skin/unit/blood DLCs.

Major DLCs equivalent to 'Rise of the Samurai' won't see sales hindered much, if at all, by modding. What it will get rid of is the nickel-and-dime DLCs that are just an insult to the fans to begin with. The truth is, if CA sets their mind towards making a DLC expansion such as 'Rise of the Samurai', modders will only embellish their hard work as they did in the days of old-- ie: merging Kingdoms Campaign Factions in MTWII mods, or by borrowing BI or Alex features in RTW mods!

CA has nothing to fear from allowing a modding community, who will only serve to make their work all the more fun and polished, to exist! Modders never work against a dev team since they are ultimately just modifying their initial base-material to begin with! If your DLC is worth being offered to a loyal fan base a modder can do nothing but make it all the greater, and free of charge.