I would say yes I think. Sounds logical to me. (PLus I saw others peaples call their "Chapters" "Tome" so I guess you can. )
I see, tho maybe i should just go the simple way and have tomes be replaced by "book 1,2,3" or "volume 1,2,3" ?
i dont think anybody would bother to complain about it aniway. You can let it be I suppose