I'm absolutely not a GM and I'm not a D&D tabletop player but I try to understand things.
Let me know if I'm wrong.
I'll consider a character level 3 with a basic 1D8 weapon (average damage 4), an attack roll modifier of +3, a proficiency bonus to weapon +2.
D&D Goblins : 15 AC with shield / 7 HP
Modifier + Proficiency = 5
Dice roll needed : 10 (50%)
Hit to kill : 2
Average attack to hit and kill : 4
Total turn to kill one goblin : 1
Larian's Goblin : 10 AC with shield / 12 HP
Modifier + Proficiency = 5
Dice roll needed : 5 (75%)
Hit to kill : 3
Average attack to hit and kill : 4
Total turn to kill one goblin : 1
It looks like actually it changes absolutely nothing about goblins.
So what's the point of changing these stats except you see "75%" instead of "50%" ?
Wouldn't it be easier to stick a little bit more to the rules, and just add an additionnal +1, +2 or even +3 bonus to the attack roll if you're higher instead of an advantage (+1 means +5% chance of hit, +2 means +10%, +3 means +15%).
Or maybe just decrease the AC but not changing the HP so combats are faster ?
Your math is inaccurate. That warrior with that attack roll modifier would also get +3 to his damage rolls meaning his avatage damge wouldnt be 4 but 7. Not to mention that dnd is a game about dice. You will get high rolls, you will get low rolls. For a fighter for that weapon however (D8 damage die) 4 and up (so half of the possible die results) instantly kill that goblin. Also goblins have leather armor alongside their shields with a dex mod of 2 gives them that AC15. The ones with bows would be easier to hit because of the lack of a shield.
Now try to 1 hit the Larians Goblins with the same fighter. Even with a crit its almost impossible to 1 shot them. And the few times that it does happen mean that you cant rely on it beeing an effective tactic.
Also some other lvl 1 spells that easily
CAN kill Goblins in 1 hit: magic missle, burning hands (3d6 in a cone, auto hits but dex save for half), Eldritch blast (with the bonus from your casting mod mind you. which ive seen most warlocks take), Chromatic orb are some easy examples that could do it no problem. But even CANTRIPS can 1 shot Goblins under normal circumstances in pnp dnd.
In bg3 atm though? Non of that applies. Goblins are a threat because of their numbers and because they may ambush unsuspecting targets. Here though theyre also a threat because you cant kill them fast enough and because they still have those numbers that they would normally have. The spellcasters added ontop of that throw even more mud in the water. They should be quite rare for goblins but most groups in the camp have at least 1 if not more spell casters amongst their numbers.
