Did they replace the Horseman's full mechanical arms to Grapple or did I read that incorrectly?

I own the german version of "Arsenal", and yes, there it says grapple. I believe this to be an Errata and am kinda sad about it...

Too bad, I liked to convert my Horseman to a small mech with manipulative hands and upgraded cyberlimbs.

Get an Iron Will.

I like the Iron Mike, personally. Will is just to wishy-washy.

Ask your GM about upgrading existing mods to better ones by paying-the-difference.

Our group uses that with turrets all the time, and it's kind of expanded to everything else.