@chris_henry How do you stop “double screening” by multiple moves? Take 3 forces A, B, and C. Force A is a standard force attempting to invade Sumantra. They move into the sea zone around Sumantra establishing a screening force and an invasion. Force B moves into the sea zone around Sumantra and announces they wish to continue into the seazone around Calcutta to engage in a naval action. Group C moves into the sea zone around Calcutta and announces a amphibious assault.
If force A wins both B and C complete their moves. The phasing player nominates Force B to conduct their combat first and if they win Force C can invade. Effectively producing a double screen.
If both B and C must contribute a ship to screening in the Sumantra sea zone then a single ship can be assigned and as long as Force A wins the move still completes. The current rules needless complicates movement with this either or logic which is not very enforceable as the rules are written.