Isometric Tilemaps Error

I am making an isometric 2D game, as I have found an asset that satisfies the ideas I have in mind. I know C # programming but little about Unity, especially in 2D, however I have documented myself and made the necessary changes to create the 3D illusion in a 2D scenario: isometric tilempas "Z as Y", I raised "Y" to 1 , adapted the grid to the angle of the tiles (Y grid cell size), in the tilemap I switched from "chunk" to "individual" (I didn't use the "2D tilemap extras"). Despite everything, the problem remains in matching the various elements of the asset, which slightly overlap the previous one (they slightly degrade), creating annoying asymmetries, especially in the tiled floor, where the rhombuses are cut. Furthermore, I have even more difficulty in matching small pieces of furnitures such as books, vases, candles, etc, due to the constraint imposed by the grid squares, which forces you to place an object in a precise box, which often does not match with the furnitures. For me, it's a bit problematic since I had to make objects appear in random points or some objects on the scenery should move (maybe I should do a hybrid scenario: sprites / tilemaps?) Considering that it doesn't look like the usual isometric 2D asset to me, but it almost seems designed to be used as sprites rather than with the tilemaps system, but maybe I'm wrong about that.
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Thank you for your help.