That is a very good question. Many people ask this when deciding their budget.
It depends on each person:
In my case, the answer is yes, this is the best use of my food ( see notes )
Note: 1 harpoon every 2.76 days is for illustrating the lost iron. Currently my largest iron sinks are emblems and upgrading my base.
I am glad you are still improving your titan teams.
We have been fighting 6* titans for 2 years. Most of my alliance is F2P or just VIP Pass. There appears to be a naturally occurring paywall caused by lack of 4* ascension items, and 5* Heroes.
3*+18 / 4*+18 Heroes appear to be more help for class quests, rare quests, and raids, then they do for titans.
Except for 1 harpoon per titan, I fight titans with 1*/ 2* Battle items. My titan battle item budget is fairly lean.
I am glad you still have heroes to level in your roster that add fun new special skills.
I have actually stopped leveling red heroes. Currently I am feeding red 1* / 2* heroes to any color hero with 8/8 special skill.
When I can spend food to trade for/ summon 5* HotM ( or Guardian Falcon ), then I will have to reassess my food budget.
This is very true.
I have a rough idea ( see notes )
Notes
Click for notes
Quotes
Link
(Troops: keep levelling 1 of each color or level a few of each color? - #7 by Gryphonknight)
FIN