Artillery is obvious, but CAS doesn't appear to have played a very big factor outside of British operations, and even then, it wasn't their focus as much as the usual operations for bombing and escorting. It's true that there was air superiority, but some of it seems exaggerated, at least in discussions I have had with other people who research them more than me.
I wouldn't dismiss Porsche at all, he had generally forward thinking designs at a time where materials were scarce and Hitler was getting increasingly exceptional with his requests. The Tiger (P) is a decent design for a tank, and I wouldn't discredit it based on a peepeepoopoo tank destroyer modification, it wasn't built for that. With some more development time like the Panther got, it would have been perfectly usable, most of the issues arose with being relatively untried tech. Hell, the Maus was a terrible concept but it didn't suffer as badly as other superheavy designs.
Also fun fact. The Tiger II (P) is a real thing. 3 Hintern tanks got made and were somewhere in Himmelsdorf, if I recall correctly. Gaijin is holding back on adding VK vehicles, but it'll be inevitable.