Not my rankings, just to compare:

Hornsby .358 avg, 1.011 OPS, 2930 hits, 301 HRs, 2 WS
Collins .333 avg, .853 OPS, 3315 hits, 47 HRs, 6 WS
Morgan .271 avg, .819 OPS, 2517 hits, 268 HRs, 4 WS
Gehringer .320 avg, .884 OPS, 2839 hits, 184 HRs, 3 WS
Alomar .300 avg, .814 OPS, 2724 hits, 210 HRs, 2 WS
Sandberg .285 avg, .796 OPS, 2386 hits, 282 HRs, 0 WS
Biggio .286 avg, .809 OPS, 2741 hits, 250 HRs, 0 WS (now)

I'm going to make a fudge guess if Biggio plays two more years:

Biggio .283 avg, .805 OPS, 3073 hits, 286 HRs, ? WS

Personally, I'd still have to rate Hornsby and Collins 1-2 even though there are a lot of +- factors between the game played in 1910-1930 and the game today.

Of the "modern day" second basemen, you could make a case for Morgan or Biggio as the top two in the Post WWII era.

FWIW, I won't even factor in Jackie Robinson because there are too many odd factors such as the late start to his ML career, the switch to 1B later, etc. It's best to just appreciate him for what he was and not try to get into any type of statistical discussion with him.