From: Vancouver WA USA
I'm a newcomer to this series and played US Pacific, US Marines, and Morning Sun on the default level 2. I just replayed US Marines on level 3 to see what the levels changed. In all campaigns, I haven't had to do restarts or cheat codes yet. In general, conservative and economical play seem to carry the day.
The US Marines scenario 3 Munda Point nicely illustrates the problem with getting and staying ashore. My notes say level 3 started me with 32/0/13 land/sea/air CPs. I stuck with fast infantry (heavy inf always lags behind an advance), but the 32-mod-3 lets you sub in one armor. I usually stick with ground attack aircraft and hold 3 or 6 air points in reserve to see if I need fighters. The 13-mod-3 lets you buy an air recon. There are no naval points, but on map are one CA and 2 DDs, and 4 supply ships.
I send the CA and 2 inf to the northeast deployment, and start working south- clearing all the way to the eastern flank. There's more deep water in the north, but I usually get a bloody nose when I try to use the CA to challenge the Jap landing force. That diversion seems to take its time coming from the northwest to the north central port.
Everybody else lands on the southwestern beach. The first few turns are always nail biters as the enemy swarms. Stand shoulder to shoulder, try to advance a hex row to create a buffer zone to retreat / rest/ replace broken units, and defend. Use the air and DDs to weaken exposed attackers, and counterattack only when you can get some kills as you work towards the river.
You've established a beachhead when you take the city, and High Command rewards you with more command points. I reinforce the northern effort with 1 or 2 inf, keep a couple more at sea in the south for a possible flank end run, and reinforce the main effort with the rest. I stick with inf and maybe armor when the CP remainder works out right.
Note you can use air (no airfield or carrier) and the map edge exit points for repair / refuel. Units exit back into your force pool, and can be rapidly shifted to distant deployment hexes. You can also change the mix between fighters and ground attack.
The eastward ground advance is a steady slogfest- tactical goals are rack up kills, keep your flank clean, and have the seaborne units keep pace. When the battle for the southern airfield is in hand, I split off a couple of columns to start marching north along the inland roads. These are timed to meet the northern group, who has cautiously advanced to keep from getting swarmed.
The final battle for the north central port is joined with the superior forces of the 2 inland columns and the northeast column. A western column advancing along the coast road gets there in the final turns. Last time, I got pissed at the enemy activity in the northwest corner and sallied with my seaborne forces. I took the air base, but the casualties and RPs were probably not worth the campaign bonus.
The next scenario Op Bliss/Goodtime is my favorite. In a nutshell: the raiders operate independently and will never join the battle for Mono in time. Stay off Mono until you've cleared the smaller Sterling Island- then pivot everybody north. Same problem getting and staying ashore, and more CPs are given when you take the victory city. I use those new resources to land on north Mono, while flankers are walking up the east & west coast roads.
BTW, there is more activity for this series on the Slitherine forum.