Using a trigger to change a unit’s attack, armour or range results in broken and weird results.
Open Scenario Editor
Place any unit. I used Amazon Archer
Set a trigger to increase (add) unit’s attack by 25
Set a trigger to increase (add) unit’s armour by 25
Set a trigger to increase (add) unit’s range by 25
Start the game
Notice how none of the values make sense. The unit has -3 attack, over -200 armour and only +17 range.
For sake of comparison, see the screenshots from AoE2 HD. Strangely, the range is +17 but the rest of the values look fine and as expected.
Apparently, when you change the unit, some values also change.
Who knows what else is broken in the trigger system. One thing is for sure, it is now impossible to make genius scenarios like in old AoE2 HD or older versions.
I found another problem. If I use the modfy attack trigger, use add and to increase attack and then use another modify attack trigger using add then the later trigger overrides the first instead of them adding up as I would have expected.
You’re setting the attack/armor types incorrectly.
If you want to increase the attack of a unit with pierce attack, the Armor/Attack type should be 3. If it’s a unit with melee attack, the type should be set to 4.
Likewise, if you want to add melee armor, type should be set to 4, and 3 for pierce armor.
Yes, it’s less convenient than in HD, but it’s the price to pay for a much more powerful scenario editor. For example in DE you can modify attack bonuses with the modify attack triggers, which was impossible on HD.