Arin Potential vs Lloyd
So from season 4, it seems like the narrative of Arin is definietly his spinjitsu as its consistently about how he learnt spinjitsu in dr s1 and how he made a new technique based on it then s2 he was called as spinjitsu prodigy or something by Sora then s3 he was called by Egalt (same guy who taught him Motion which Spinjitsu is motion) to hage potential and Lloyd said hed be one of greatest and S4 Euphrasia calls him spinjitsu specialist and we see his spinjitsu being used in various ways further signifying and in s1 when He was doubting himself, Lloyd would say you taught urself spinjitsu u can become one of greatest.
Also, Arin potential is based on greatest not strongest. Assuming greatest = strongest is false assumption objectively. Arin can become the most skilled with spinjitsu and it was also confirmed by doc that Lloyd could create his own martial art so its not really proving anything and from S4, we learnt that Lloyd powers are connections meaning if his connections get stronger and closer to him, he gets stronger aswell.