I am trying the later July of 1861 now.
Pros
1. You can build some extra units for Northnern Virginia and/or the West. It looks like you can accelerate the historically available forces a bit better. The one thing that irks about this game as compared to old board games like Victory games' The Civil War 1861-1865 is there is no Army ZOC. It seems like the union can move past the Army of the Potomic at will. Movement was restricted when armies were near in the old board games. Now entrenchment levels might the army itself doesn't.
2. Army of the Potomic and Shenandoah get some entrenchment will forming I believe.
3. You can possibly have more money and war supplies if play correctly.
4. Interior decisions begin in early June so you can sacrifice extra units for industry. It appears that if you don't build a thing April to July you will have the same units as if you start at late july 1861.
Cons
1. The union often moves forward earlier ahistorically. I have small units attack AOP as early as May. I am not sure if this is too agreesive AI sometimes I see them get aggressive for Norfolk and sometimes they sit back. This maybe more about detection but with forces right next to the AOP you would think they would have good intel. Not 100% sure on that I used the AOP to attack Alexandria once because there were only about 400 power there and the AOP was 2X that size. By combat it was over 1300 power not sure if reinforcements arrived or it was bad intel. This was prior to corps so MTSG.
2. Fort Sumter never surrenders after bombardment. Despite getting the message about Ft Sumter histrocially surrending my Caroline dept spends considerable time besieging the place.
3. For a newer player there are too many options some good some bad some neutral. You have some good options to expand industry. Some bad options to build things like gunboats in SC which are limited use and some neutral options like building more militia.
4. The west is a little harder. You start with Price's force the future West army in Johnson City MO. and holding Rolla. I am lucky to have him in Springfield by July of 1861 and hold Rolla and Johnson City with a brigade each.
5. The first turns are little boring.
6. If haven't played this before it is a little hard to build to make your divisions later. You get a lot of scripted forces and you build non-optimally in some areas not realizing the game is going to give you some free units. it takes a game or two to learn what the game is going to give you for free. So it is frustrating in the beginning having a plan for builds and then realizing you may have wasted some builds particularly in the west because the game is going to give you some free units.
I am not sure there are strong advantages to starting in April 1861 you can build forces up a bit more than what you would start with in July and have them trained by late July since the building begins in late May of 1861. However, there are some headaches that you miss. In my experience so far I usually wind up a little more secure in VA and less secure in the West. There can be lower run advantages to putting WS and money into industry a bit earlier but it is at a bit of a short term cost. Well balanced? There seems to be less ability to have historical abberations and customizing your armies like in the Hearts of Iron series but then again in HOI you start in 1936 and have 3 years to research techs and build forces before the war historically begins.
I do think I wouldn't recommend starting a grand campaign in April for a brand new player. Too many decisions when you haven't played enough to really plan them out well. I think for experienced players the ability to play cards, build forces, and have industrial decsions a couple of turns early is a plus. I am not sure it is huge but a plus. Most newbies probably won't be able to put that into a coherent plan.
Starting in 1862 doesn't look bad but you miss the historical opening of the Kentucky campaign.
