I've looked into the Delay Effect in RRG 1.6 page 15. It states
Some abilities contain delayed effects. Such abilities specify a future timing point, or indicate a future condition that may arise, and dictate an effect that is to happen at that time.
• • Delayed effects resolve automatically and immediately after their specified timing point or future condition occurs or becomes true, and before responses to that point or condition may be used. Delayed effects have the same timing priority as constant effects.
• • When a delayed effect resolves, it is not treated as a new triggered ability, even if the delayed effect was originally created by a triggered ability.
This leads me to believe that Delayed Effect still, in fact, triggers before Retaliate. Even if it triggers as a constant effect, player should be able to pick the sequence as it triggers in the same timing windows.
RRG 1.6 page 5 under "Ability"
Simultaneous Timing Priority — Some abilities have timing priority over other abilities. In order, the timing priority of abilities with the same triggering condition is:
1. Constant abilities, delayed effects, lasting effects, keywords, and icons.
2. Status cards.
3. “Forced Interrupt” abilities.
4. “Interrupt” abilities.
5. “Boost,” “When Defeated,” and “When Revealed” abilities.
6. “Forced Response” abilities.
7. “Response” abilities.
8. Consequential damage.
Keep up the work, you're doing really great job!