Hey, seems like you don't know a few things.^^
As a beginning statement: Please always put a replay, if you post such bugs. I never had any such problems, so it is difficult for me to fix any of them. But it also seems that some of them are not exact bugs, but are part of the map itself and are also quite important.
First of all there is sometimes an upper boundary of most troups, so sometimes less troups spawn, such that there won't be too many troups on the field at once. Most of the attacks are divided in two teams and sometimes only one of the teams appear at once and the other appears later. Basically at every spawn, the game tests if the team already exists, if not, then it spawns the team. If it exists (maybe from an earlier attack, which is still attacking you), then it won't spawn the team until you have defeated the team (but then it will spawn the team at that point in time)
This is done mostly as it saved some ressources form the energy, but it also would cause bugs otherwise. A workaround would cause an increase of around 30-50% more scripts. And this is huge.^^ So I think it is way better if the troups just spawn after you have killed them.
Also the heavy armor sounds like a bug, which made the map easier than intended - after some time all uruks from random attacks should have those that upgrade. Period.^^
Also those attacks do not have anything to do with holding the wall - only the timing is different.
The attacks for a destroyed wall are completely different - mostly those additional attacks are warg riders.
To be more precious, the following attacks exist for the fallen wall:
Wargattack 1: 14 Wargrider hordes
Wargattack 2: 10 Wargrider hordes
Wargattack 3: 7 Wargrider hordes
Ballista attack: 11 Ballistas
Combo attack: 10 combo hordes
Combo attack: 7 combo hordes
Combo attack: 5 combo hordes
The exact timings are:
If the wall falls after 20-200 seconds, then all 7 attacks appear. (+instant +4 Levels, Blades and Armor)
If the wall falls after 201-360 seconds, then all warg attacks, the ballista attack and combo attack 1 and 3 appear. (+instant 4 Levels and Armor)
If the wall falls after 361-600 seconds, then Wargs 2 and 3, Ballistas and Combo 1 and 3 appear. (+instant 3 Level and Armor)
If the wall falls after 601-900 seconds, Wargs 2, Ballistas and Combo 1 and 3 attack. (+instant 3 Level, Armor)
If the wall falls after 901-1100 seconds, Wargs 2 and Combo 3 appear.(+instant 3 Level and Armor)
If the wall falls afterwards none of the above attacks appear.
In addition Mines will always appear if the wall gets overrun.
Also the random attacks are exactly the same from the beginning until the end, there are 8 attacks per side- The only difference is that there are times, which activate upgrades. Basically there is a script, which says: "If a timer expired and this team has been spawned, then give him upgrade X (or give him Y experience levels) This may not be true for some of the non-random attacks. Also sometimes ugprades are given earlier, if the wall falls, for more exact parts look below.
The random attacks start after 30 seconds, the attack time is always 250 seconds with 100 seconds downtime. ("Time of an attack" means: 4 Teams spawn, if they don't exist from the previous attack (each team contains multiple hordes) and if a full team dies within those 250 minutes, it will respawn - that's what I meant above with "They will spawn later")
So it may be that less troups spawn, if it is exactly the same attack as the one before, but then most likely some of the teams will have a high chance to die in that time and the troups will just spawn a bit later - so they will spawn, but not right at the beginning.
The possible melee attacks are:
10 Uruk hordes
5+5 Uruk Hordes
6+6 Uruk Hordes
10+10 Berserkers
10+7 Wild man hordes
9+9 Orc Hordes
3+3 Uruk Crossbow hordes
3+3 Uruk Crossbow hordes
10+7 Uruk Hordes (this sounds buggy, I will fix that.)
6+6 Uruk Hordes
6+6 Uruk Hordes
10+10 Berserkers
8+7 Wild man hordes
9+9 Orc hordes
4+2 Uruk Crossbow hordes
3+3 Uruk Crossbow hordes
Basically for all of those attacks hold:
They get forged blades after 8 Minutes and 20 seconds
They get heavy armor after 18 minutes and 20 seconds.
They get 1 additional Level after 4 minutes and 10 seconds
They get 1 additional Level after 8 minutes and 20 seconds
They get 1 additional Level after 18 minutes and 20 seconds
They get 1 additional Level after 23 minutes and 20 seconds
All of the timers start as soon as the first uruks spawn.
Please also note that the upgrades are not given immediately at the spawn - they are given after they left the spawn area, so as long as a single unit is still in the spawn area and has not left it (sometimes some of them are left a bit behind), they have not gotten their upgrades yet.
As said above, it can always be that some of the scripts have an error (hence only some of the troups have upgrades), but I never had such a problem.
(small edit: I just made a quick check and the heavy armor was always spawned for all 4 Uruk attacks with 12 units)
So it would be nice too know what kind of message came before the uruks with no armor in LG appeared, as I could use that to find the error rather quickly.
Then, often a victory in that challenge will be partially due to the fact that we had some luck, and that we had not the hardest waves against us.
As said: The game is actually balanced for those harder waves and people managed to win with those on hard mode.^^ The easier waves are actually a bug.
I thought at the beginning that by keeping the wall even longer, those insane waves would not appear but I was wrong. They always can appear even if you did not anything wrong, they are not like punitive waves.
As said above: Replay would be nice. For me and all of the games I saw from other people, those waves worked perfectly fine.
What I would fine very nice is putting all random waves without heavy armors at any case and add a fixed number of attackers with heavy armors who would come along each wave (for example, 3 additional Uruk Hai batallions or 2 additional Uruk crossbowmen with heavy armors).
As said, they are time based. It is always that either all of the units have the upgrade or none of them. (that would also be way harder, as it would cause a ton of additional work for the engine)
Overall thanks for the feedback.^^ It looks like there were some bugs in your map (at least all of your problems should not be in the map like that) and as usual: Please a replay. Otherwise I could sit another 40 hours on the map without any chance to find them.^^