The fact that someone used stereotypical Indians before you is a poor reason for using them yourself. If a tradition or custom is wrong, repeating it also wrong. If you haven't heard, two wrongs don't make a right.
If your customers wanted the '60s Frito-Lay game featuring the Frito Bandito, would you repeat that stereotype too? Probably not. Therefore, I suggest you not repeat the Native stereotypes. You're responsible for the choices you make, not your customers.
I didn't say the images were derogatory. I said they were stereotypical. They depict a tiny subset of old-fashioned Indians from a couple of centuries ago.
Nor are the images accurate even for traditional Plains Indians. All your Indians, including a chief and what looks like a maiden, are half-naked. Indian chiefs and women didn't go around with a lot of flesh exposed.
Do you disagree that your Indians are stereotypical? If so, go ahead and make your case. If not, admit you're perpetuating stereotypes.
This doesn't even address your game's association with the stereotypical Chief Wahoo. Or with the phrase Wahoo Indians, which I believe is derogatory. Really, there's nothing positive about calling a game with Indians "Wahoo."
I recommended you get rid of the Indians altogether. If you feel you have to use Indians, pick four representative Indians from different regions (Northwest, Southwest, Great Plains, Eastern Woodlands). Or four individual Indians from these regions (e.g., Chief Joseph, Geronimo, Sitting Bull, Tecumseh).
I doubt your customers will know the difference. As your website indicates, people have produced several versions of Wahoo with different Indians. Why would buyers accept only one version of the game when they accepted several versions before? Where's the evidence that people won't buy anything but your stereotypical Indian version?
And no, I don't count your Mesoamerican version of Wahoo as a valid test. One, Mesoamerican Indians look pretty strange to most Americans compared to North American Indians. Two, of course people are going to buy the more familiar game if you offer them both. The real test would be to offer only a nonstereotypical game and see if your sales drop off significantly.
If you want to be more daring, use four modern Indians. For instance, Vine Deloria Jr., Wilma Mankiller, Dennis Banks, and Winona LaDuke. Market it as a new and improved version of the game. A nonstereotypical version that will enlighten as well as entertain. Who wouldn't be impressed by this version's potential to educate children?
In short, there are several reasons to change the game and no (good) reason to keep it the same. I suggest you change it, Chuck.