refactor random_permutations for simplicity

alpha-reorder imports

fix broken import

smartsim/entity/strategies.py

@@ -56,21 +56,10 @@ def step_values(
 def random_permutations(
     param_names: t.List[str], param_values: t.List[t.List[str]], n_models: int = 0
 ) -> t.List[t.Dict[str, str]]:
-    # first, check if we've requested more values than possible.
-    perms = list(product(*param_values))
-    if n_models >= len(perms):
-        return create_all_permutations(param_names, param_values)
-    else:
-        permutations: t.List[t.Dict[str, str]] = []
-        permutation_strings = set()
-        while len(permutations) < n_models:
-            model_dict = dict(
-                zip(
-                    param_names,
-                    map(lambda x: x[random.randint(0, len(x) - 1)], param_values),
-                )
-            )
-            if str(model_dict) not in permutation_strings:
-                permutation_strings.add(str(model_dict))
-                permutations.append(model_dict)
-        return permutations
+    permutations = create_all_permutations(param_names, param_values)
+
+    # sample from available permutations if n_models is specified
+    if n_models and n_models < len(permutations):
+        permutations = random.sample(permutations, n_models)
+
+    return permutations