Efficient use of swords: AL3 or TC1

I was trying to figure out what was a better(more efficient) use of swords. Using them in Alchemy lab to convert to backpacks then producing heroes in TC2. It wasn’t immediately obvious just looking at the game so I decided to plug it into a spreadsheet. Still not sure I am 100% correct but here is the results I came up with.

Assumptions
Alchemy lab is going full out one way or another.
I use all the swords I collect.

So for alchemy lab I either use 8 swords + other stuff + 815.5K of food = 124k food/day vs Alchemy 4U 415K = 60K food, so 64K extra food to produce the backpacks/day. If your alternative is 7U then there is only a 30K food differential.

TC1: 8 1* 1.6K8=12.8K to produce
TC2: 4 2
, 4 1* 2.0*8 = 16K to produce (assume 50% probability of each)

TC2 will generate on average 1.8X the experience of TC1 for a given number of training. (also takes 3x longer but I am ignoring that part)

Analysis results: The metric I used is Experience/1K food. Food usually seems like the bottleneck rather than recruits or other resources.

Use for training:
This is variable so I was trying to figure out breakeven points.

Conclusions:
Cases where AL3 is more efficient:
All 1 and 2* are getting dumped into 5* where the training cost is >8.9K/hero. The efficiency gets better the higher the cost.
If the alternative in AL is one of the higher level upgrade conversions then the breakeven is quite a bit lower to the point where as long as you are not differentiating between 1 and 2* for where the hero goes to training AL3 can be more efficient.

Cases where TC1 is more efficient:
1). training cost is <8.9K/hero
2). You do any sort of split training where 1* are more likely to get dumped into a 3* or 4* or low leveled 5*.

Notes:
At 10K/hero training cost AL3 is about 4% more efficient. At 12K it is about 11% more efficient in terms of total food cost.

Just thinking of off color training with 10K/hero training cost
For AL3 a total cost/day of 160K food for 8 swords for experience gain of 2160
For TC1 a total cost/day of 92.8K food for experience gain of 1200.

Bottom line for me is that based on this analysis most of the time unless I need more backpacks to keep TC2 running continuously I would lean towards using swords in TC1 vs in AL3 since food always seems to be in short supply. TC1 does take a lot of recruits so if that is more of an issue it might tip the balance a little more towards AL3.

What are other peoples thoughts on which one is better: TC1 or AL3 for sword usage?