Trinm,
Circling back to your original question.
Using spray cans requires very careful control. Hardware store type spray paint cans result in thick paint applications if not used "sparingly". These paints are designed for total coverage in one or two coats. Having a few runs on a repainted barbeque is acceptable; on a battleship hull it's not.
It's much more successful to use hobby specific spray cans. There aren't too many choices; Testors and Tamiya and maybe a few that I don't know of. Either of those are very good. It's important to follow basic procedures; warm can, warm ambient temperature, clean surface.
Brush painting is also effective, and a good skill. Painting something as large as your Bismark would be a challenge, certainly not something to try without experience. If you look at the British hobby mags, those modelers brush paint a lot, in particular aircraft models.
Enamels brush well, acrylics don't. But acrylics airbrush as well as enamels, and in a way with less fuss.
Try Tamiya AS-25 Dark Ghost Gray, AS-26 Light Ghost Gray, TS-33 Dull Red and TS-68 Deck Tan.