drawing from pictures is excusable for me if you have no other means of drawing the vessel. if there is already an shipbucket drawing of the vessel, you have an high chance that one is more accurate then what you can draw from pictures.
for redrawing an existing shipbucket drawing, I myself only thrust general arrangement plans and building plans of the navy which operates the ship or the yard which build it, unless I can prove the original drawing is off quite a lot, in which case drawing from for example friedmans are acceptable to me. if no other sources are available, I can of course always try to draw the ship from an sketchy plan or even an picture, but that is the final option to me.
hope this helps