The HOMM 3 HD mod works with the GOG.com version in Crossover 13.2.
https://sites.google.com/site/heroes3hd/
I prefer playing in a window so I can also have a web browser or the PDF manual open.
I use with "Use legacy X Window System" checked (Crossover Advanced tab) and "Emulate A Virtual Desktop" set to 1920 x 1080 (Crossover Control Panel tab ... Wine Configuration ... Graphics)