Carl,
The T&T rods use a single line designation, which is put into the more common double line designation the other manufacturers have used to date would have the 1409 designated as a 14' 8/9. The GLX has been using the common double line designation, so the 14' GLX is rated by Loomis as a 9/10.
The Loomis GLX and the T&T rods are pretty close in stiffnes and butt strength although they have different flex profiles with the GLX moving into the butt just a little quicker than the T&T and the GLX has a faster recovery rate than the T&T rods. Therefore, with the T&T 1409 and the GLX 14' 9/10, you are comparing rods rated for two different line wts. The T&T is rated for on line wt less than the GLX, which is why they use different sized lines.
Regarding Sage, I've found that if you take line weight the model number uses as the line to ballance the rod (instead of the commonly listed by fly shops and catalogs double line designation) they work best. In other words, the Sage 9141 should be considered to be a 9wt rod (not a 9/10 wt rod); thus it is best ballanced by the 8/9 lines.
As can be seen from the above, the T&T 1409 and the Sage 9141 are 9 wt rods (or 8/9's as the more commonly seen double line designation would be) and the GLX is a 9/10 (or actually a 10 wt) as it is designated.
As for how Loop rods are designated, I find I prefer to use the line number listed on the rod as the higher of the two common double line designations that has been in use on lines. Thus, the Loop Green 1409 would also be an 8/9 rod like the T&T 1409 and the Sage 9141.
Before I get beat up over this, keep in mind that those who are new to spey casting and those who like a higher load on the rod and resultant deeper bend usually like these rods with the RIO "B" line recommendation, which is one line size higher. And this puts the RIO "A" and "B" recommendations for these four rods exactly in line with the above.