Split is not implemented correctly

[Fuco1]

  let mandatory_mod1, mandatory_mod2 =
    let mod1 = Pool.pick pool in
    let mod2 = Pool.pick pool in
    match mod1, mod2 with
      | Some mod1, Some mod2 -> mod1, mod2
      | None, _ | _, None -> fail "cannot split an item with less than two modifiers"
  in
  let other_mods1, other_mods2 =
    List.partition (fun _ -> Random.bool ()) (Pool.to_list pool)

This could create a split with 1 and 4 mods for a 5 mod item. That can't happen. The recipe in game also states

Split an Item Into Two, With Half the Mods on Each Item

So it will be (2 and 3) or (1 and 2) in the odd cases.