No I'm not saying its speed shouldn't be 90, I'm saying its speed isn't 90. That thing seems waaaaaaay faster then 90 speed and for its length. You can especially tell in a duel with someone that uses. Take Rhaelys for example.
Rhaelys uses the Great Long Bardiche last I checked, and yes, I already know that it's faster than it seems. Same thing applies to the greatswords.
Consider this: Higher weapon weight and higher damage lessens your chances of glancing. Because of that your weapons sweet-spots can be stretched. In other words, you can turn into your swings to connect earlier in the swing arc and still maintain full damage. You should know about this considering you use a Sword of War.
Simply put, weapon speed is a worthless stat to bother thinking about if you know how to turn into your swings properly based on your damage and weapon weight. Why do you think 2-handers can pull of double swings so easily and not 1-handers?