THoT-S3: make AI sides smarter (#9992)

- Side 2 will be less reckless and more defensive
- Side 3 will avoid making stupid moves, like placing units on water for easy kills

Co-authored-by: Tahsin Jahin Khalid <5283677+knyghtmare@users.noreply.github.com>

data/campaigns/The_Hammer_of_Thursagan/scenarios/03_Strange_Allies.cfg

@@ -61,15 +61,34 @@
         facing=ne
 
         [ai]
-            # Make our allies stupidly aggressive;
-            # keeping Marth-Tak alive anyway is part of the tactical problem.
-            {NO_SCOUTS}
-            passive_leader=no
-            village_value=0.3
-            aggression=0.8
-            leader_value=3.0
-            caution=0.3
-            grouping=offensive
+            passive_leader=yes
+            village_value=1
+            aggression=0.40
+            caution=0.60
+            grouping=defensive
+            retreat_factor=0.40
+            retreat_enemy_weight={ON_DIFFICULTY  6  4  2}
+            [goal]
+                name=protect_unit
+                [criteria]
+                    side=2
+                    canrecruit=yes
+                [/criteria]
+                protect_radius=12
+                value=100
+            [/goal]
+            [goal]
+                name="target_location"
+                [criteria]
+                    x=17-25
+                    y=18-23
+                    radius=4
+                [/criteria]
+                value=100
+            [/goal]
+            [avoid]
+                terrain=Ww*
+            [/avoid]
         [/ai]
     [/side]
 
@@ -97,21 +116,26 @@
         [ai]
             passive_leader=yes
             recruitment_pattern=scout,fighter,fighter,archer,mixed fighter
-#ifdef HARD
             [goal]
                 name=target
-                value=100
+                value={ON_DIFFICULTY 60 80 100}
                 [criteria]
                     id=Marth-Tak
                 [/criteria]
             [/goal]
-#endif
+            [avoid]
+                terrain=Ww*
+            [/avoid]
         [/ai]
     [/side]
 
     {STARTING_VILLAGES 1 3}
     {STARTING_VILLAGES 2 9} # Give Marth-Tak all villages south of the rivers.
 
+    # these sides spawn the Orc Assassin way too much
+    {LIMIT_CONTEMPORANEOUS_RECRUITS 2 ("Orcish Assassin") ({ON_DIFFICULTY 4 3 3})}
+    {LIMIT_CONTEMPORANEOUS_RECRUITS 3 ("Orcish Assassin") ({ON_DIFFICULTY 4 5 5})}
+
     [event]
         name=prestart
 
@@ -144,6 +168,11 @@
                 bonus=yes
                 carryover_percentage=40
             [/gold_carryover]
+
+            # let player know that they have to flank and attack the attacking orcs
+            [note]
+                description=_"Your ally will focus on defending."
+            [/note]
         [/objectives]
 
         [unit]