No, to add to the "Other Versions" of a certain beyblade, usually the face, CW (and maybe even MW) might need to be similar. I am not sure about this, though. But yes, the constellation/character represented by a certain bey must be similar, to be able to call it another version of the other bey. This means that the Face has to be same. It may also imply that CW might be same. But, there are some exceptions to the 'same CW' theory.
The Spin Track and Bottom are the most unimportant things when considering beys for "Other Versions".
About Killer Beafowl, the Other Versions may be certain recolors of Killer Beafowl.
What you want to add does not belong to "Other Versions" but it can be added to this-
http://wiki.worldbeyblade.org/index.php/...Track_List
And yes, you may say that Killer Beafowl should only be bought for collection purposes.
The reason is, the only Competitive Part it offers(EWD) has now become easily available through a more useful (and expensive) Strongest Blader Set.
I hope this was helpful!
Team IB Revolutions
Thanks to N0body for the avatar and Synth for the signature!