For reference, here's a rough comparison between the Island branch and the Fleet branch, assuming strong path and ideal choices. I didn't bother adding the last Tower Knot points that are the same in each branch.
The Lord of Blood island branch also assumes that either Sabitha Armies OR Mestan Island is on, and that the player won't fulfill the conditions for the Sabitha scene. Yeah, assumptions are starting to pile up here, goal is more to give a general idea than to be a perfect tool to choose between the two. Also, likely bias due to being a comparison in a vacuum, ignoring the costs and benefits of previous choices.
LoB branch | Fleet branch
Create Tower weakness | Damage island |
IW_VP + 6 | IW_VP + 7 | IW_VP +5
IW_LoB -3 | IW_LoB -5 | IW_LoB -3
IW_Nyst -2 | | IW_Nyst -1
| | IW_Fuzkao -1
| Crimson Sword |
Crimson Orc Sword OR Crimson Vibrator |
Twisted Charm |
Ginasta +2 | Sabitha +1