Not sure if this will help but if you go to steam reviews a person going by the name of Sabreman has written this:
"VOL 2: FOOTHILLS OF THE GODS -- same as 2013 COPs1: Battles for Greece; not much reason to upgrade if you’ve got that. Includes about half of 2006 “Airborne Assault: Conquest of the Aegean”, but with upgrades to engine and missions. Very mountainous missions (colorful terrain); lowest average unit count and smallest missions in series so far. Probably the best bet for new players. Obviously a lot of early kit for the sides. The missions focus entirely on the Axis invasion of Greece, with the Italians (in a few early missions) and the Germans (in most of the missions) trying to punch through the United Kingdom defenders (primarily Austrailia and New Zealand, farrrr from home) while they attempt to spare the Greek forces from annihilation. And then the ANZACs must evacuate the area when everything falls apart. Features the last major successful airborne missions by the Germans.
VOL 5: THE CAULDRON -- never released for COPs1; finishes porting and expanding the AA:COTA missions to the new engine. UK and local allies defend Mediterranean islands and early Tobruk North Africa against Axis, throwing out the Italians and then trying to prevent Rommel's arrival from crushing Tobruk. (No actual Tobruk missions tho.) Lots of sandy waste, plus small island fighting (Malta, Leros, and a major Crete campaign). A little larger average unit mix than FOTG. Ends before Operation Torch.
VOL 8: PATTON’S CHARGE -- not yet available (probably summer 2017), this first pack since the Steam launch will follow Patton’s campaign across southern France post-Normandy, eventually in parallel with the Market-Garden pack, up to (apparently) some small Bulge missions not otherwise included elsewhere. The key characteristic will supposedly be large maps with low unit density (even if not necessarily low numbers of units) for lots of maneuver opportunity. Probably not meant for beginners.
VOL 1: HIGHWAY TO THE REICH -- highly polished missions from 2002 game "Airborne Assault: Red Devils over Arnhem". If you bought the 2012 expansion to Command Ops 1, probably no reason to rebuy. There are certainly improvements since the 2003 version, also called AA:HTTR (much moreso since RDOA). Missions range from fairly small to seriously large. I'd recommend doing this one 3rd. Once you're good with the large missions here, you can handle anything else.
VOL 7: WESTWALL -- a direct sequel to HTTR and somewhat paralleling the forthcoming PATTON’s CHARGE, this pack features attempts in the autumn of 1944 to break through Germany’s defenses. It naturally serves as a prequel to the Battles of the Bulge. Battles are larger than average. The earliest mission in the pack explains what American ground troops were trying in their own daring thrust during Market-Garden; the last mission hypothesizes action in a historically quiet sector at the start of the Bulge. Between missions focus on scrambling efforts by the Germans to stymie thrusts into Germany around Aachen and out of North Holland (where Market-Garden ended up), along with counter-attacks to uproot Allied possession of Holland staging areas. I recommend new players wait until you buy and finish HTTR.
VOL 6: KNOCK ON ALL DOORS -- a specialist set of Bulge battles, meant for highly experienced players, featuring very large maps and the highest unit counts in the official missions (so far). The twelve missions are grouped into three sets of four, each set focusing on the action of one of the three German armies launching operations at the start of the Bulge (or the Allied troops in their way, played from that side). The theory of the mission pack is that the success or failure of each army was decided within 48 hours, so the missions are much shorter than average for packs so far. Each army, broadly speaking, features the following variations:
1.) a historical goal and unit mission lasting 48 hours from 0500 on the 16th until 0500 on the 18th.
2.) a historical goal and unit mission lasting starting at 0500 on the 17th, but running to evening on the 18th. (These are the only variants with an alternate time range, the idea being to advance the clock to the start of significant fighting.)
3.) a hypothetical goal set (the titular “Knock on all doors” plan) for broader attacks to test for weaknesses and then to adjust advances for exploitation. (“Knock on all doors and see which ones open.”)
4.) a “Knock on all doors” goal set, with strategic reserves committed to help each army.
VOL 3: RIDE OF THE VALKYRIES -- northern half of the Bulge missions originally released with COPs1. If you bought COps1, probably no reason to get this.
VOL 4: BASTOGNE -- the southern half of the Bulge missions originally released with COPs1. If you bought Cops1, probably no reason to get this."