How would the game break if one used a "single initiative" system?

[larsdangly]

Probably the best thing about playing TFT RAW is that you are presented with a lot of situational choices that influence outcomes pretty strongly, so there is definitely a skill to playing well. Combine that with the generally balanced power level of the game, and high degree of vulnerability everyone/thing has, and it means your success or failure depends more on you and less on some brute force advantage your character's stats or equipment might provide. A lot of the ways you might imagine changing game tend to dilute that strength, I think.