Your assessment is incorrect.
Using theoretical BiS build of:
Build 1: http://ffxiv.ariyala.com/NGQV for DET
Build 2: http://ffxiv.ariyala.com/NGID for CRT
Bio's damage value per tick with Build 1 using the current damage formula including CRT + Maim and Mend 2: 141.8901
Bio's damage value per tick with Build 2 using the current damage formula including CRT + Maim and Mend 2: 142.5040
Bio II and Miasma's damage value per tick with Build 1 using the current damage formula including CRT + Maim and Mend 2: 124.1538
Bio II and Miasma's damage value per tick with Build 2 using the current damage formula including CRT + Maim and Mend 2: 124.6910
Fester's damage value with Build 1 using the current damage formula including CRT + Maim and Mend 2: 1064.1758
Fester's damage value with Build 2 using the current damage formula including CRT + Maim and Mend 2: 1068.7805
If you factor in the difference in the Spell Speed difference as well, Build 2 will yield about 1.5% more damage than Build 1. That's also excluding the difference in Enhanced Pet actions procs, which in itself is harder to quantify.