(page 53) The next line of that interview quote:

Eight of us managed to do it. The next time we attacked, we could jump.

And the footnote:

Interview with ISWAP Commander-7, 2025. While this may seem extreme, the episode reflects a pattern evident across other interviews, in which the group absorbed heavy casualties during dangerous experimentation and training.

It sure is wild; but humans aren't the expensive thing for Boko Haram I guess?