Yes, it's possible, but you can't give a non-Hero unit the Strength, Agility, and Intelligence attributes.
But you can just increase the stats directly: hp, mana, attack damage, hp regen, mana regen, movement speed, attack rate, etc.
Here's an example:
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Set Neutral Level to Life Percentage
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Events
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Time - Elapsed game time is 0.00 seconds
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Conditions
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Actions
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Custom script: set bj_wantDestroyGroup = true
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Unit Group - Pick every unit in (Units owned by Neutral Hostile.) and do (Actions)
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Loop - Actions
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Set VariableSet Neutral_Unit = (Picked unit)
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Set VariableSet Neutral_Percentage_Life = (Percentage life of Neutral_Unit)
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-------- --------
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If (All Conditions are True) then do (Then Actions) else do (Else Actions)
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If - Conditions
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Neutral_Percentage_Life Less than or equal to 99.00
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Then - Actions
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Unit - Set Unit: Neutral_Unit's Integer Field: Level ('ulev') to Value: (Integer((Neutral_Percentage_Life + 0.01)))
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Else - Actions
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-------- --------
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-------- Get the Level and convert it to a Real so we can modify it easily: --------
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Set VariableSet Neutral_Level = (Real((Unit: Neutral_Unit's Integer Field: Level ('ulev'))))
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-------- --------
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-------- Get our bonus stats -> 4% more hp per level, 2% more mana per level, 3% more attack damage per level: --------
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Set VariableSet Neutral_HP_Multiplier = (Neutral_Level x 0.04)
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Set VariableSet Neutral_Mana_Multiplier = (Neutral_Level x 0.02)
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Set VariableSet Neutral_Attack_Dmg_Multiplier = (Neutral_Level x 0.03)
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-------- --------
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-------- Apply these bonus stats to the unit (if it's higher than level 1): --------
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If (All Conditions are True) then do (Then Actions) else do (Else Actions)
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If - Conditions
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Neutral_Level Greater than 1.00
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Then - Actions
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Unit - Set Max HP of Neutral_Unit to (Integer(((Real((Max HP of Neutral_Unit))) x (1.00 + Neutral_HP_Multiplier))))
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Unit - Set Max Mana of Neutral_Unit to (Integer(((Real((Max Mana of Neutral_Unit))) x (1.00 + Neutral_Mana_Multiplier))))
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Unit - Set Base Damage of Neutral_Unit to (Integer(((Real((Base Damage of Neutral_Unit for weapon index 0))) x (1.00 + Neutral_Attack_Dmg_Multiplier)))) for weapon index: 0
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Else - Actions
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-------- --------
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-------- Restore it back to full HP after all calculations have been made: --------
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Unit - Set life of Neutral_Unit to 100.00%
This gives Neutral Hostile units 4% more HP, 2% more Mana, and 3% more Attack Damage per Level.
So a Level 5 unit gets +20% HP, +10% Mana, and +15% Attack Damage.
In the example map I have two triggers. The second (disabled) trigger is setup to only work for
non-Hero units and you can add more Conditions to it to filter out unwanted units like Structures for example.