Win rate: 75.50% (151/200 manual trials)
Croc: 67.48%
Difference is 4.0s at 50/24 risk threshold

Standard fight: 7 turns (6 + slower than both) + 5.2s lost to Magnitude text + 2.5s lost to NVE text + 0.1s lost to cry + 1.0s lost to X item
Croc standard fight: 6.5 turns (6 + slower than Miltank) + 0.5s lost to more damage
Difference is 11.3s

So Geodude is 7.3s slower on average

unless...

Rollout strats

Win rate: TBD
Standard fight: 5 turns (4 + slower than both) + time saved to fast Defense Curl turn + time saved to no re-select move

About 14 seconds faster than Magnitude strats (from manual timing + estimating)

12.2s to get Rollout
11s to teach Rollout
12.5s for Arnie route

IF ARNIE:
+35s fight
+2s deposit egg in Violet
+10s repel uses
-5s Miltank (included in calcs above though)
-30s movement
-4s no Cut R36 grass
-0.5s L20 for Sudowoodo
-?? money (probably very little)

IF NO ARNIE:
+10s movement
+5s repel use
-2s no Route 36 encounter