Normally, kenshi with aggressive style and strong spirit will be put in senpo position to set the rhythm of the team. The weakest player will be in jiho position since it won't affect much when losing the second match. Kenshi in chuken position has to have a calm mind and strong spirit. He is probably the most important after taisho because if the team already loses two match, he has to be able to stop the momentum of the opposing team. In case the team is up two matches, he should be able to maintain the momentum. Consequently, chuken position requires kenshi with experiences, someone who is able to play different styles of kendo. The fukusho position and taisho position usually are left to the two strongest players of the team. Taisho is the most important position when both team are of equal strength (the match will come down to the last man).
However, in case of a weak team fighting a strong team, using this arrangement won't work. It is normal to expect that the strong team will use the arrangement as described above (let's call it the traditional arrangement). To be able to deal with such arrangement, the weak team has to stack their strength up front, meaning positioning their 3 strongest players in first three position (senpo, jiho, and chuken) in the hope of settling the match early. They will put the most aggressive player in the senpo position, the strongest player in chuken position, and the second strongest in the jiho position (he must get two points since jiho of the opponent team is expected to be the weakest player). As for the fukusho and taisho position, the two remaining players of the team have to play defesnsively, avoid loss at all costs (if they lose, they can't lose 2 points).
Playing defensively means to close the distance between you and your opponent, stick with him all the time, move around, do not allow him to set up, mess up his timings, and pray to God the clock runs faster.
Anyway, there are a lot of variations of arrangement depending on who we are playing.