Our games normally see the Germans build some fleet (including a couple tpts). Agreed Gibr gives many options (no AB makes it somewhat riskier), but if US comes to Norway via Gib (they can see it coming), then the Germans can delay it by simply building (or moving) a dd off coast of Normandy (sz 110) to block them for a turn. So the US (if is still going north) will normally kill the dd (move to sz 110), and have the UK build a carrier (add/planes) to try to keep the Germans from hitting them (provided the UK is still in the game). Then the US can probably take Norway (UK can land air to def), but the Germans again can be ready to counter it from the Baltic. Again our games usually see some navy builds for the Germans, and the western allies will need a good sized fleet to get close to shore.