wow! that does sound like a neat idea! I have never known anyone to have done such a thing, but my current DM has run The Red Hand of Doom (in it's original setting) and then our next campaign after that was in Age of Mortals Dragonlance (but he did not blend either of the 2 together). We used D&D 3.5 for Red Hand of Doom, and then in the Dragonlance "Key of Destiny" campaign he amalgamated Pathfinder + house rules to play it instead of 3.5.
I do not know how such would be done, but if anyone finds a way, I'd love to hear about it, also
I do not know if my DM has an account here but I can ask him how hard the task would be, when I see him again tonight.
Tangent: I myself am preparing to run MY FIRST EVER campaign with the War of the Lance (Dragons of Autumn, etc...) campaign in 3.5 so I'd love to have input
ok I asked him about this issue last night. My DM gave this advice:
1. Replace all the half-dragon NPCs with nothing but draconians. IF you do this, you will have to make sure you are not playing in any time period before Age of Despair, as obviously draconians did not exist before then. Also consider replacing any hobgoblins with draconians too (unless you are placing it before Age of Despair as above noted).
2. Keep account of which NPC and PC classes are being used in the game, ie: Mystics (Favored Souls) are not allowed in-time (they never occurred) anywhere before the Age of Mortals, so unless you were playing in Age of Mortals (or thereafter), then you'd have to change them all to some form of Clerics only (or maybe even a spell-casting Knight of some kind - maybe Knights of Takhisis/Neraka or Legions of Steel, or even blackguard / fallen paladin (which are extremely rare, being that Solamnic Knights (any variant/order) are the only true, original "paladins" of Krynn, other than the Ergothian Cavaliers in the Age of Dreams, from whence they came).
You would have to change 1 of the NPC enemy bosses, Karn, in respect to points 1 and 2 above, because he was a half-dragon favored soul (which did not exist either racially AND class-wise, anywhere in Krynn).
Otherwise, the whole campaign is fairly generic and should just plop right down into any world/setting/time period (even during the War of the Lance, as a concurrent/parallel adventure, if you wish) as long as you reviewed everything about it that would not be age-appropriate for Krynn (by "age-appropriate" I mean the things that were going on in each HISTORIC AGE of Krynn, being: that which was allowed or not allowed per the WOTC/Sovereign Press Hickman/Weis campaign setting guidelines/books).
There may be more to this but ask me questions and i can ask him again, as I have likely forgot other things he said to me last night.