So my ls mate told me to switch mnk for Sam "it would be faster"
I don't know why people believe this, but it's just not true, unless we're comparing like a Stage 5 SAM to a non-Prime MNK.
Seeing as how your attack is capped, these fights will be short. You have Warcry from WAR too, so you will have massive TP overflow. SAM benefits less from Warcry due to their TP overflow with Zanshin. With Footwork (you should have it for full fight), you will obliterate any boss, or Howling Fist if you fear making an unfavorable SC. I would be shocked with those buff if you don't hit 3-4 80k+ Tornado/Dragon Kicks/Howling Fist and a strong Raging Fist (if you are cycling to break up wall). MNK would also add Chi Blast which makes bosses less dangerous in that short zerg, and Mantra gives WHM a little more breathing room to keep people alive, especially vs Gartell. Now while SAM has the advantage of Yaegesumi vs Gartell, Gartell can still kill a SAM through his SP2 by countering an attack or landing a buffed up melee attack. MNK's Inner Strength gives you 100% Guard Rate, so Gartell probably can't kill MNK as easily as it can SAM, or maybe not at all with Chakra and the huge HP chunk you get for 30 seconds.
I'm not saying SAM isn't incredibly strong, but the myth that "SAM is faster than MNK" as a blanket statement is just not true.