While I was learning the perek, I found all the changes in girsa overwhelming. But now that I'm chazering it, one thing becomes very obvious.
The whole perek is about fringe korbonos: temurah, v'lad, mafrish nekeivah l'(korbon that's only male like olah or asham). And in all the cases, three tanaim have mostly the same positions: (1) R' Elazar says you can actually bring it as a korbon, if it's eligible. (2) The chachamim say let it graze and redeem it, and bring the korbon with the money. (3) R' Eliezer says let it die (תמות).
There are lots of exceptions, but they never really change places, just shift over to a neighboring position.
Given that this is generally true, it's very understandable why the kadmonim are changing the girsa right and left. For instance, they change every single R' Eliezer on some pages to R' Elazar, both in the gemara and in Rashi. Because if the position (bring it as a korbon) is a R' Elazar-dik position, they assume it must be him. And so too throughout.
The whole perek is about fringe korbonos: temurah, v'lad, mafrish nekeivah l'(korbon that's only male like olah or asham). And in all the cases, three tanaim have mostly the same positions: (1) R' Elazar says you can actually bring it as a korbon, if it's eligible. (2) The chachamim say let it graze and redeem it, and bring the korbon with the money. (3) R' Eliezer says let it die (תמות).
There are lots of exceptions, but they never really change places, just shift over to a neighboring position.
Given that this is generally true, it's very understandable why the kadmonim are changing the girsa right and left. For instance, they change every single R' Eliezer on some pages to R' Elazar, both in the gemara and in Rashi. Because if the position (bring it as a korbon) is a R' Elazar-dik position, they assume it must be him. And so too throughout.