The fact that SE refused to make TH3 an additional re-roll says to me that they are unwilling risk throwing off the balance they believe they have created. Nothing would throw that balance off more than adding 10% on top of an item that they want to have a 1% drop rate. If anything they would want TH procs and +1 gear to effect rare drops less than common ones. Don't forget what game we're playing amirite? My admittedly also baseless theory is that every +1 over TH2 counts as a 1% increase to the items base drop rate before re-rolls. In other words an item with a 5% drop rate with TH3 would have a 5.05% drop rate or with TH12 it would have a 5.5% drop rate. My LS has done 60+ fafnirs since the ground kings change all with TH9+ and we have gotten 0 ridills. Even if ridill has a 0.00001% drop rate, under your theory, ridill's drop rate would be increased to 7% at TH9 which it pretty clearly isn't.
