So I bought FE:LE and I've been playing it for a week. I'm finding it to be a lot of fun (especially with all the choices you can make customizing faction/hero/units). I had read on another thread that factions played by the AI will try to incorporate custom player units into their production; this got me all giddy... and then I spent a few hours trying to optimize unit designs for all the default factions (for now).

This got me to thinking, however - I've noticed that any time I finish researching techs that for new equipment requiring metal/crystal, several of the default unit types automatically upgrade to that piece of gear - regardless of whether or not the faction has sufficient resources to build the new equipment (due to metal/crystal shortage). This practically locks me out of training those types of units until I can gather enough resources to train them with the new equipment. Personally, I think this might affect the AI playstyle a bit (assuming the same thing happens to them), because their choices may be potentially limited once they research certain Techs.

A prominent example is Enchantment, which is an early game Tech - the player may not have sufficient crystal at this point in the game, but almost all units are already upgraded to the new magical weapons (exception is Militia and potentially any sword-wielders). There's a similar case with the Weaponry Tech, but I think metal is a bit more plentiful so it's less of an issue.

I think I can alleviate this by making multiple unit designs at each general tech level (leather/chain/plate with weapons at similar tech level, use metal only, no crystal), but it tends to be a bit tedious, is inefficient and floods the Train Unit window with similar, slightly redundant designs. So, I have a suggestion: Is there a way the game can be coded to downgrade to the next available equipment if their metal/crystal resources are not sufficient? For example, Defenders will not upgrade to lightning hammers until they have enough crystal; they will roll back to the next available hammer type depending on available resources. I imagine this will be ongoing thing, not a one-time switch - so if you have enough metal/crystal to upgrade and then run out at some point in the future, the unit design will accommodate for the shortage.

So , that's the primary point I wanted to discuss! There's a few other details to note:

1. A warning message might need to be put in if you're queuing multiple units and somehow run out of metal/crystal by the N-th troop that you're trying to build, otherwise the player may unexpectedly be fielding weaker troops than he/she expected
2. Not certain how it would be implemented if you had a downgraded troop queued and you just gained enough resources for it to upgrade again - I think it's best that the queued unit remains downgraded so as to not confuse the player when he sees resources magically disappear. Also see point 1.
3. Accessories should be implemented the same way upgradeable weapons/armor is - downgrade to previous item if resources not available. If those types of accessories are not available due to unresearched Tech (this would be the case if you were starting a new game), then it should be removed entirely. An example are the different tiers of fire/ice attack accessories, both of which require research first to unlock.
4. I suppose this brings up the question of what should be prioritized depending on if there are resources sufficient to produce only the weapon or armor specifically - I think in this case it should be weapon over armor, but that may be debatable. For armor specifically, shield should be prioritized first and then chest.
5. Something probably needs to be done about the Chain Mail/Plate Armor traits - it should check for whether or not that armor is even available for upgrade before the trait is added to the unit cost. It's adding anywhere between 15-50 production cost for training a unit. EDIT: Perhaps that trait should be redesigned as a single trait that scales production cost up or down depending on what armor the unit will currently equip. It will just automatically take up a skill slot and add cost if required.

One last thing - I'm seeing a bug for the Monk unit under the Amarian faction. It's not upgrading to the Sindarin Staff when it's available. The unit just sticks with using the staff.

Took a while writing this post, if someone ended up making a mod that fixes this, then I probably wasted 20 minutes typing this

Thanks for reading! Let me know if there's anything I haven't considered or if this is isn't particularly useful to implement.