Actually I think the most elegant solution would be to lock the quad package behind company command post, leaving the current M5 where it is. That way you could grab it (very) early and pull off reinforcement / bren bus shenanigans- makes for interesting options instead of hardlocking it behind a CP count- then convert it into cheap AA / anti harassment later on.
Company Command Post is too late to be impactful. The idea is to give UKF an anti-infantry shock unit.
If keeping the non-upgraded M5 at the current timing is desirable, you could bundle the base halftrack with the M10 (Lend Lease Vehicles) and make the M5 Quad unlock a CP3 commander ability in its own right.