This turtle guide was good, and I understand you aimed it at newer players, but there are some Event Eidolons that could replace the SR Dragoons:
Resheph (Wind Resist)
Fleurety (Thunder Resist)
Rahab (Thunder Resist - actually I used to think Rahab was COMPLETELY useless, because who would fight Thunder with Water? Turns out she substitutes the Wind SR Dragoon in a turtle build)
I mean, using SSRs instead of SRs would mean less of a stats compromise.
EDIT: Realized the SR Dragoons are used for the 3t/8t CD... And those Event Eidolons only provide 10% resistance at FLB while Dragoons give 20% at FLB and Kaisers 30% at 0LB. So yeah, bigger defenses in this game surely mean less offense - those Events Eidolons would be in a middle.