vanilla item texture replacement

hello, sorry if this has already been asked somewhere, but i searched and couldn't find any relevant info... i'm very new to datapacks - my understanding extends to being able to run /execute and /item commands in the tick script :P
i'd like to know if it's possible to use CustomModelData to replace the texture of an item with a custom nbt tag, but instead of providing a separate model, can we just replace it with an existing texture/model? to be specific, can i make a datapack that tells minecraft to render a carrot on a stick with the custom data "tag:1" as something else already in minecraft, like an echo shard?
thanks for reading!