>>34585646defensive stats would be irrelevant, speed would be mostly irrelevant but appreciated and situationally important (say, outspeeding and OHKOing the only enemy pokemon carrying a super effective attack) and more attack would be largely irrelevant but appreciated and situationally important too (OHKOing a threat that could KO it back if it survived Shedinja's attack like a wall using toxic on it).
Ultimately, It would be a slightly helpful but mostly irrelevant buff, because Shedinja's entire purpose is to serve as a wincon by being literally unkillable by removing its counters, in which case its own stats and the stats of the opponent are all irrelevant. Honestly? Just give Shedinja Sturdy as a hidden ability. People say wonder guard should be buffed to also ignore passive damage like magic guard, but I disagree. Since Shedinja's HP pool of 1 means literally any single instance of passive damage kills it, making it literally immune to direct attacks and only killable by direct damage makes much more sense.