Koutetsujou no Kabaneri will be one cour show.
They will announce show 2016 summer(and later) show at March 17's conference.
There are some cases where animation studio animated episodes out of order.
As example, Studio Guts said they are subcontracted by Bridge to do episode 10 of Seisen Cerberus on their Twitter.
Do tell me what great 1 cour original shows you've watch, Comet Lucifer?