A shell of the real Goddard, after the Smith defeat Joe was finished, too old, too drunk. Sharkey had great attributes but he wasn't a massive puncher but no feather puncher either, just not a Maher, Choynski or Fitz. Or a Sullivan.
And either man would be Sullivan's best win. How good of a puncher was Maher? He could not stop Ruhlin in three fights, drawing twice and getting Ko'd the 3rd time. Some think Maher his harder than Sullivan. So would Choynski, whom Sharkey defeated. And then there is Goddard, whom Sharkey Ko'd but Sullivan did not meet. Sharkey was even with Corbett as well. Sullivan has a very thin record, and his finishing power disappeared in the mid 1880's. This much is for certain, Sharkey proved the better chin, and fought 3x the competition. On point on Sullivan which I see but no one else mentions is there were very few big punchers in his day, he must have really stood out.
You are basing this on what exactly? For all that you know, Jake Killrain might have beaten them both in the same evening!
Ruhlin wasn't really a top fighter when Sharkey beat him, it was only later he really developed. Ruhlin lost to Sharkey between losing to Kid McCoy and goin life and death with Ed Dunkhorst.
Does this mean that you find Sharkey overrated overall, or underrated in some other aspects? According to the writeups, he basically lived and died by his power, conditioning and toughness.
Fitz took him out twice. I 'd put Sharkey right up in the mix of top contenders of his time, maybe a bit like Rex Layne in his?
Sharkey was tough, fit, brave, dirty, determined, rough with great stamina and will. He was a decent puncher, no more.