Samurai 8's been mostly placed in that year-long+ zone alongside Yui Kamio so far, where it'll get a decent length run due to there always been stuff more worth cancelling. TSS is a full on flop however, maybe it's doing slightly better than Taisei and Beast Children but the 3 are taking up the bottom 3 every issue. It might get past 1 cancellation batch but definitely not two.
I think Samurai 8 will get a full run unless sales are utterly disastrous (which is very unlikely), it's only planned for 10 volumes anyway which is, what, 85 - 90 chapters? That's pretty reasonable for an eh but not awful performing series, Remember Dance Club lasted for 10 volumes with not impressive sales and mostly low rankings later on. Heck, Spring Weapon got 7 volumes and it performed worse than a bunch of quickly cancelled stuff.