I mean, If you're afraid to Increase The movement speed of the Merc suit, for fear that it'll unbalance the Speed of the non combat (And slightly combat) areas of the Game, Why do you not worry about things like the Troikas being the slowest (And hindering the combat ability in SOOOOO many ways) and Ancient slowing you down even more, and not holding up well to the Damage you throw at us?
It seems as though you tossed the Damage reduction to balance the stun... But then what is the speed nerf for? Yeah, it fits VERY thematically, I'm not asking you to change that... I'd just love to see some major compensation for the Speed issues.
The speed of the troika means that it's far too easy to be interrupted in the middle of the attack, making the low damage hit that you set up so carefully Fail. Hard. All of that is now gone in an instant.... and it sucks. It also leaves you Wiiide open to any sort of attack in general. So in all, it makes monsters harder to kill, and you far easier.
As to the armor? Well, It not only makes it easier for you to be hit at anytime, it slows your attacks, and hinders dodging. On top of that, it protects you from almost nothing- the exact opposite of what was intended. In all, it slows down your gameplay, hinders your ability to not get hit, and then makes you take more damage.
Where is the bonus to the Slow that you've introduced? If speed changes are big, then shouldn't a major speed detriment call for a bonus of some sort?
~Tsu
In a more ideal realm of balance being slower would be rewarded with larger and stronger attacks (heavy swords having wider swing ranges and allegedly more powerful attacks), high tanking ability (Plate lines are supposed to do this but fail miserably) in exchange for attack speed and/or movement speed (get damage buffs, lose speed buffs), and be more threatening one on one ("Striker" versus "Guardian", latter should win).
However, seeing as offensive benefits are already assumed by "Striker" equipment, that leaves "Guardian" with the only option remaining: defense. A lazy fix would be to slap more defense on Plate lines, maybe give a damage buff to Troikas or something bland. Does that help the "Guardian" protect team members or themself? If your defense only helps yourself, how are you guarding your team? You would be down some damage and speed benefits that a "Striker" would have, so what do you contribute?
And then this.