removing sub animations would be taking a step backwards which would be unfortunate. if one would think about it for a sec using a separate object is not always the best way to go. in fact, it would be cumbersome in some situations adding extra events and conditions to check for zorder, collisions and various other things that should be done in the animations. if you think about stylized games where the object is morphing in the animations the separate object isnt what they do.
currently you can set up your entire game engine based on what you see your character currently doing through animations reacting to what is seen on the screen which would make sense. sub animations take up less space in the animation bar and creates easy state machine that no one knew about because no examples were given.
some examples here
including simplest state machine thingy without arrays or variables
can also be used in a way to separate two characters (or character modes/forms) in one sprite.
download last then 2nd then 1st:
last (basic) just shows simple sub animation.
2nd has comments and new animations allows decision for going in two different directions with animations control everything in practically one event.
1st is 2nd example with its comments removed and 2 more animations down another sub level (= 3 levels of sub-animations).
keep in mind in the 2nd example instead of going only left-right you could add as many states as you want to loop thru as long as animations are still in parent but anything that jumps out of parent allows new sub actions under the other parent and are totally separate. this is all done without variables.