Let's talk about B Rank Tomeliths.
In Seal Rock, B ranks aren't that great - you shouldn't ignore them, but you should seriously consider how many points that B rank is actually worth to you. If you control one from 100 -> 0, is worth 80 points, in 40 ticks of 2 points. Realistically, they'll be worth 0-50 by the time you get a tag, which is barely worth your time if everything goes perfect.
What you should be doing, however, is attempting to flank the other teams. If the other two teams are fighting, and you can flank at an angle that lets you retreat, it's almost always better to prioritize kills rather than B ranks.
Kills are important for a few reasons - they stop fever from building up, they scatter enemy forces, and, most importantly.. they're worth a lot of points. A kill is always worth at least 5 points, and realistically at least 10. Even a handful of kills is better than flipping a B rank node, and a slaughter is worth as much or more than an A, if you're getting Highs/Fevers.