you believe that TnE is closer to CT than MgT is despite the d10 or d20 rules system? TnE is at best a cousin not a sibling.
Really just looking at your list I am stunned. MgT not as closely related to MT or CT as T4? You do know the die rolling conventions used in T4 no? rolling multiple dice and even rolling half dice to get under a number...
You're misinterpreting a label. DGP-CT is a particular DGP add-on, and was not part of CT proper.
CT DOES NOT HAVE A TASK SYSTEM. Every skill has its own resolution system suggestions, and several adventures have very different methods for skills.
MGT's task system is as close to CT proper as the DGP-CT Task system... and in both cases, that's quite a leap... but MGT's task system is further afield than TNE's, by simple dint of incompatible task labels making MGT not directly useful with tasks from other editions. In short, it's a wholly separate branch of the tree.
the DGP tasks for CT became the MT task system directly, and with a change in dice use, 1d10 instead of 2d6, the 2300 Task system. Tasks from any of the three are useable in any of the three without changes.
TNE tasks have the same difficulties, and substantially the same skills, but a different system for time. The mechanics of resolution are different, but the difficulty vs baseline skills are comparable success levels. (Difficult Tasks being 7- on 1d20 is 35%, vs 9+ in DGP-CT and MT (10/36=27%), and 8+ =30% in 2300. In T4, that's 4d for 9-, about 30%.
DGP-CT, MT, and 2300 can use Stat+Skill, Skill+Skill, or Stat+Stat; TNE, T4, and MGT can not
by the book.
a MGT Difficult is an expected 9+ as well... but the labels don't line up.
MGT's levels (DM for the 8+ roll) {Effective Roll Needed} {Adjusted for stat7 and skill 1}:
Simple (+6) {2+} {2+}
Easy (+4) {4+} {3+}
Routine (+2) {6+} {5+}
Average (+0) {8+} {7+}
Difficult (-2) {10+} {9+}
Very Difficult (-4) {12+} {11+}
Formidable (-6) {14+} {13+}
Note that different time is an order of magnitutde change for a DM±1 in MGT. This means that Mr. Av Stat, skill 1 can just make a formidable in MGT
Vs DGP-CT (Roll needed) {With Stat 7 or skill 1 in both components}{Extra Time TN}
Simple (3+) {3+ due to minimum nat 3 to succeed} {3+}
Routine (7+) {5+} {3+}
Difficult (11+) {9+} {5+}
Formidable (15+) {13+} {9+}
Impossible (19+) {17+} {13+}
TNE is a multiplier system with a 1d20 roll... the expected stat 6 skill 2
Simple x4 {19-, as a 20 fails, or 32-, depending on GM interp.}
Routine x2 {16-}
Difficut x1 {8-}
Formidable x1/2 {4-}
Impossible x1/4 {2-}
Extra time shifts one level easier.
TNE works, aside from the means of calculation, very much like the DGP task system. MGT doesn't. Being unskilled is far more a penalty under DGP-CT, MT, 2300, or TNE than it is under MGT. Extra time is far more powerful under DGP-CT, MT, 2300, or TNE than it is under MGT.
Not all DGP-CT, MT, nor 2300 tasks can be exported to TNE, T4 nor MGT, since the latter require 1 stat and 1 skill.