OK, not sure what you're trying to achieve then, because if you click on the tilemap you can set tile width/height and offset X/Y.
Sprites are different from tilemaps. If you click outside the layout, you can select 'snap to grid', etc. on the left properties bar. Those are similar settings to tilemaps. Those settings are what makes sprites 'snap'. Tilemaps have their own settings.
Also keep in mind, sprites usually have the image point in the center of the image, if you put it top left for instance, you can neatly snap them in the layout grid.
Perhaps you could show your problem with a .c3p? An example project will suffice.