Yup this would be the best way I think. They spawn with 4 sten guns and you can upgrade to 2 thompsons. 0.8 received accuracy out of cover.
I would also replace their mills grenade with the commando smoke grenade, so they have smoke and phosph nade. Both get unlocked with the mills package.
The current assault package from lend-lease doc just sucks
Not only is it the best idea, it's also the only one that is somewhat realistic. At this stage it's not like they are going to implement a colonial squad or welsh division that would require new unit design and voice lines. But making a different variation of an existing squad like 0 CP assault sections would not be completely outside the realm of possibility.