How Agility and Strength work in game for infantry.

[YunYun]

But walking into your swings or turning into your swings makes you hit your oppenent faster for sure; although its not stats related, its related with your skills with a mouse and keyboard.

Yep I totally agree, but ...

No increase for swing speed by agility

I'm pretty sure it does increase swing speed. I could be wrong but I honestly think it does (saw that in Native).
But I'll create a charac with 5000 Agility in Native, to test it.