I feel the foundation for enough "tactic" is there:
Stances, Staredown, Predict, Center.
It is just not really tight.
Predict is way too "costly" in term of action usage for what it does. Too easy to avoid by the opponent for the insane cost of 1 full action it took you to do.
Centering is ok, but since you cannot crit with Iai Kata, it seems like a wasted action because you cannot draw a weapon while centering, do not make a check, and have to use a non-defensive void stance. Too hefty of a cost without the guarantee of a solid followup attack that can bypass earth stance or win you the duel.
Staredown is a solid mechanic that gains more and more traction as the players raise in ranks and offense becomes exponentially better than defense (for duels).
Stances are all fine except the earth stance which provides a bit too much of stalling in duels to first blood/hit.
All in all, it ain't that bad! My houserule to Rising Blade basically fix all of these aside the Predict action which stays kind of useless (I think).
Sure it makes Rising Blade the kata of choice for Duelists that are specialised in winning first blood/crit duels which are aptly named.. IAIJUTSU duels. Though, heart piercing strike kata valid contender.
But, it hardly makes the other strategies unviable. Especially not for Warrior's duels or duels to the death.
With the pressure of the Rising Blade, and the difficulty to achieve the severity 5+ after resist of this kata, the risk vs reward of duels is real.