That would be my guess as well although what happened during Wolverine Vol.2 #1000 could also explain why the Weapon Plus project went with animals experimentations for Weapon II.
In 1945, Logan decided to infiltrate a Nazi facility in order to take down the man responsible for the death of his unit: the General Wolfram. This guy was experimenting on Nazi soldiers and was turning them in werewolves thanks to a "Super Soldier" serum he created. Logan stopped him and was about to kill him but Fury stopped him saying he needed this psycho alive for the Weapon Plus program:
So yeah maybe Wolfram joining the Weapon Plus program influenced them to go with animal experimentations for Weapon II after seeing his "success" with werewolves. I'm reaching a little here though lol, I'm sure the most logical explanation is what you've said.
Lmao at the Power Rangers reference! He didn't take it very well in this issue, but yeah he was always supposed to be the first of many until the whole thing was twisted like norj said.
You're welcome!
As explained by Fantomex, the programs weren't contiguous, they were concurrent:
Which could explain why the programs didn't share their notes.