Also, attack speed upgrade to what? It is not like it is faster and even if it was, the weapon itself has no calcable feats. Trust me, I looked. MHS+ plus.
Also, keep in mind that when he recieved the Murasama, Raiden could not damage before and when he did get it and started fighting armstrong, he did more damage then when he was in ripper mode.
And sure, armstrong started to lose power. However this was midway through the fight.
He still damaged him more reliably then he did previously. Thus the town level rating. Also, for leeching the power point. Armstrong always leeches power, even in the clip you showed me. This is probably more of a fighting style quirk possibly.
-Heavy Panting? Could be because Raiden is finally damaging him. If you get punched, you started to pant as well if it hit you hard enough. Could be exhaustion too, but sure lets indulge that idea.
Raiden is 1.1 kilitons. Ripper mode buffs it up to 7-9, so lets round generously up to 9 Kilitons. 9 Kiliton blade did not damage him, yet Murasama did. He also broke raidens previous hf blade. This seems to me that the simplest assumption we can make he with Murasama he is beyond 9 Kilitons by an unknown factor. Even if you say armstrong was half as strong, he would still be Small Town Level+. In other words, an upgrade.
No matter how you look it, Raiden, Armstrong and Sam seem to have some scaling that justify a town level ranking. (Although sam is more dubious, I will give you that)
Also, I wanna add that Armstrong > Excelius, right? Saying he isnt town level because he is leeching power from a machine who is barely town level, despite the arguments above is just inconsistent. It seems more likely to me Armstrong, Sam and Raiden are more likely to be town level then not.
Plus. They will still keep their Low 7-C tiers, just with possibly/likely 7-C with Murasama. Edit: Except Armstrong, he is straight up 7-C now because he took Town Level punches like a champ. Edit 2: Even in the same fight you linked me, at 6:20, he damages armstrong in fullbody coat successfuly AFTER leeching for power.