Are you saying that the Samyang is closer to the Canon 24mm TS-E Mark II than the Mark I?
In functionality yes. The Canon MkI is severely limited in the tilt to shift orientations (as are all Nikon PC-E lenses), the Canon MkII version was a vast improvement on that and offers unlimited tilt and shift orientation not only in the picture but in relation to each other, the Samyang, though obviously built to a lower price point, has the same orientation adjustments as the Canon MkII lens.
This is enough for me to recommend the Samyang. Besides, the Canon 24mm MkI is not a particularly "good" lens.