So all car manufacturers do? Assemble things other manufacturers make like engines or electric drives, bodies seats etc. the only key thing Tesla makes is the batteries. rest is assembled from other suupliers.
NKLA have already been delivering Budweiser in class 8 trucks
they have a number of key patenet and even suing Tesla over one .
Everything is laid out in corporate presentations including the partnerships that de-risk everything.
Their business case is hard to turn down for fleet managers who due to govt regulations have to keep replacing trucks.