I would think that the number of assists a defenseman gets would be indicative of their playmaking ability, not the number of assists they get relative to goals, as though them scoring goals makes them less of a playmaker. Figure that one out!
Seibert had 0.29 A/GP in his career, greatly helped by two war years in which he had his highest totals.
Shore had 0.33 A/GP in his career, greatly hindered by the no-forward-passing era in which goals were scarce and assists were scarcer.
Shore was definitely the better playmaker. But onto what you were saying, about Seibert's "assists to goals" ratio showing a greater focus on playmaking.
Eddie Shore: 179 A, 105 G. 1.70 A/G.
Earl Seibert: 187 A, 89 G. 2.10 A/G.
On the surface, what you're saying would appear to be true, but you are missing something very important: From the 1927 season through 1931, (the five seasons Shore played pre-Seibert) assists were handed out very sparingly: about 0.67 per goal. From 1941 through 1945 (the five full seasons Seibert played post-Shore) there were 1.44 assists per goal, over twice as many. In the nine seasons that their careers overlapped, the average was 1.31.
To be statistically fair to Shore, his assist totals for his first five seasons should be doubled, and Seibert's from his last five full seasons should be worth 91% of what they are. That would leave Seibert with 178 assists and Shore with 233. Their assists-to-goals ratios would then be 2.22 (Shore) and 2.00 (Seibert) - So Seibert wasn't really more of a playmaker than Shore, by any measure.
What does this prove? Nothing in particular about these players. I am voting for Seibert very highly this round, and I know that you must also know a comparison to Shore is truly silly. But this does show that statistical comparisons should not be made haphazardly without full understanding, and then disclosure, of the context.