You would have to swap one of your primary class's trees out for the Rogue tree (most likely Acrobat) to pick it up. I have serious doubts that swapping out a level 18 or 19 deep tree will ever be worth what you get from a level 1 or 2 deep tree.
I did an example earlier with my Bard. Thanks to her two splashes, she actually pulls from enhancements that are likely to be split into 8 different trees. Given that she has to take the Warchanter tree, she's probably going to want to keep the Virtuoso tree (for song enhancements), and I'd be daft to forgo a Racial PrE, those splash enhancements aren't even worth considering.