The first one is the British 40RBL78 MA Field Gun.
Its basically a chassis of an shovel excavator with a field gun on it. 1 was actually built.
And the other one is completly deranged german idea, i absolutely love it, but it would rather fit as a april fools tank, than a event vehicle.
I just leave the quotation of tanks-encyclopedia.com here for you to read:
Projekt NM:
This vehicle, known only from a single blueprint, is possibly one of the strangest tracked war machines ever designed. German blueprint HSK 3485, dated 15 June 1943, named Project “NM”, shows a monstrous and ungainly vehicle consisting of three Tiger tanks joined together by I-beam girders. Built atop the I-beam frame sits a warehouse-like structure, concealing three 150 mm cannon-armed turrets. The reasoning behind this design, its purpose, and even which branch of the Wehrmacht it was for, remains a total mystery.
