Thanks to Kensaki's ripped files, we can get a good impression of what the branches in the Langrisser 1 remake are. Previous promotional material hinted at something along the lines of Langrisser 2's Light/Empire/Independent/Chaos paths, but the demo shows a plot with 8 final branches, AH paths.
In the game files there is a .csv file that describes what characters are available to select for each level, which gives a better structure of what is what. It may be placeholder, or out of date, so it may not represent the final game. There's some very odd parts of it that make me think this file predates some final changes?
Obviously, some spoilers are ahead. I think this stuff is interesting, and I'm fine knowing structural stuff like this before playing a game without feeling totally spoiled.
A&B are the traditional light path. The slight branch near its end is a slight change to the party roster.
C&D are the first branch, just after the halfway mark of the game, while Langrisser 2 branched at about the 1/3rd mark. Unlike Langrisser 2's Empire path, this doesn't really piss off your main party members. Rias and Leticia are main party members for most of this, while the final branch determines where you get Lance and Betty or Digos. The plot looks like it uses several Langrisser 2 maps imported into Langrisser 1.
E&F are the "independent" path. This is basically the adventures of Ledin and Betty, with some sporadic additions. I can't tell at all what differs on the final branch between E&F. Files make it seem like the same party on the same maps.
G&H are the Chaos path. This pisses off some of the original party members, while ones like Taylor stick around. For some of the missions you get Bozel, Nagya, and Nicalis, but their presence is WAY diminished compared to Rias, Leticia, and Betty. Like E&F, I can't tell what the difference between G&H is.
So overall there are four main branches that rapidly split in the game's second half. Of those four branches, one of them has a fairly substantial sub-split, while two of them have very very minor splits. Not as elaborate as the Der Langrisser splits, but does roughly double the number of truly distinct scenarios/stages in the game.