In my garden I would prune both in February. That would lose the early bloom on Rosemoor but they should bloom together later in the year. Someone from your zone may have a better answer for your situation.

Some websites say that they can be treated as a 2 or 3. I hard Pruned my Rosemoor for the last 3 years and am letting it be a 2 this year just to find out for myself. It seems to be one of my slowest to get established but then again...It was bareroot when I planted it...I have Venosa Violacea planted a couple feet from my Clematis "Empress" which is a two...I hard Prune VV and once "Empress" has leafed out..I can see which are the dead vines from them having dead brown leaves then I gently cut away the old dead vines of VV from my "Empress"..I can be done..You can hard prune them both if you want and see how it does this year compared to prior years and choose what works for you and OF COURSE which methods produce the best blooming!!...Pruning and fertilizing is the key...alway fertilize when your hard prune in late winter/early spring and then again after their first bloom period is over....Jeanne