Bloodline is strong but cheap. I am afraid nerf bloodline may favor crossbow meta, which will be a smoother transition.
Generic militia tech that exclude a few civs may be a good way to buff militia-line. It seems that swordsman can never compete with archers or knights in terms of raw power. Perhaps a tech that enhance the role of infantry (cheap and fast) may work, such as reduce swordsman training time to make use of quantity to compete with archer/knight’s quality.
Or a tech that allow double garrison space for swordsman in rams without changing the original max ram speed. Or allow monks to heal swordsman faster.
Skirmisher may also receive speed buff so that it is faster than swordsman with squires to better cover militia. (can be implemented together with bloodline nerf to nerf both knight and archer?)
Though I agree to buff militia-line a bit, I am a bit worried of any buff of militia-line being an indirect nerf to Goths/Mesoamerican playstyle.
I have also proposed LS and THS +1 MA; LS onwards +0.1 speed. The final strength of champions is untouched except +0.1 speed. The only concern is Goth and meso-american playstyle.