What the title says. I used to believe for a long time that Marcus was superior to Paladin!Sain. However, I've recently considered that Sain might be able to reach reasonably high levels and weapon ranks in Lyn Mode (I've seen people reaching Lv20, B Swords, B Lances in Lyn Mode). Both of them compete for experience when both exist, and Sain requires less resources to reach important parameters than Marcus due to better growths overall, particularly speed.
Who do you believe is the better unit, and why? Is Marcus's availability more important than Sain's less resource necessity for speed benchmarks (14 AS)?