Move unit purchase off find_unittype.

game/db.py

@@ -1332,7 +1332,7 @@ def upgrade_to_supercarrier(unit, name: str):
 
 
 def find_unittype(for_task: Type[MainTask], country_name: str) -> List[Type[UnitType]]:
-    return [x for x in UNIT_BY_TASK[for_task] if x in FACTIONS[country_name].units]
+    return [x for x in UNIT_BY_TASK[for_task] if x in FACTIONS[country_name].all_units]
 
 
 MANPADS: List[Type[VehicleType]] = [

game/factions/faction.py

@@ -3,7 +3,7 @@ from game.data.groundunitclass import GroundUnitClass
 
 import logging
 from dataclasses import dataclass, field
-from typing import Optional, Dict, Type, List, Any, cast
+from typing import Optional, Dict, Type, List, Any, cast, Iterator
 
 import dcs
 from dcs.countries import country_dict
@@ -240,7 +240,7 @@ class Faction:
         return faction
 
     @property
-    def units(self) -> List[Type[UnitType]]:
+    def all_units(self) -> List[Type[UnitType]]:
         return (
             self.infantry_units
             + self.aircrafts
@@ -251,6 +251,12 @@ class Faction:
             + self.logistics_units
         )
 
+    @property
+    def ground_units(self) -> Iterator[Type[VehicleType]]:
+        yield from self.artillery_units
+        yield from self.frontline_units
+        yield from self.logistics_units
+
 
 def unit_loader(unit: str, class_repository: List[Any]) -> Optional[Type[UnitType]]:
     """