We can take Hastings the slow way with tanks, there's no need to use paratroopers there.
Though honestly, I think it'd be better to attack Churchill first, and then attack Justinian from two sides. The main bottleneck for conquering Justinian is the speed our troops can move, if we attack from two sides, we can take him on faster. Plus, there's a chance we'll have modern armor when we declare on Justinian, making it even easier.