Should I use a three-way associative table?
If I have followed correctly, the two options is whether to have one or two intermediate table for the relationship between groups, user_types and resources. The answer, from a purely design point of view depends on whether that relationship is a strong or weak one. In other words, if groups_user_types (lets call it authorizations) is something that should exist if one of the other entities do not, and if an authorization is shared between resources or not. Let's see an example:

"manual1" can be accessed by: 


painters in group a
foremen in group a
painters in group b


manual2 can be accessed by:


painters in group a
foremen in group a

resources
---------
id|name
 1|manual1
 2|manual2

user_types
----------
id|name
 1|painters
 2|foremen

groups
------
id|name
 1|a
 2|b

groups_user_types
-----------------
id|group_id|user_type_id
 1|       1|           1
 2|       1|           2
 3|       2|           1

groups_user_types_resources
---------------------------
resource_id|groups_user_type_id
          1|                  1
          1|                  2
          1|                  3
          2|                  1
          2|                  2



You know your application better than I do, but I do not see groups_user_types as a strong entity (no attributes, no reasons to exist if  groups_user_types_resources disappears). Maybe I am wrong, and permissions is a big part of our application, and you will give each resource a named authorisation that can be shared between resources. But if not, you can change the last two tables into:

    groups_user_types_resources
    ---------------------------
    resource_id|group_id|user_type_id
              1|       1|           1
              1|       1|           2 
              1|       2|           1
              2|       1|           1
              2|       1|           2


Again, this depends on how strong groups_user_types is and if those permissions are shared between resources or not. Are the permissions for resource 1 the same entity that the same permissions for resource 1. Will you have lots of resources with the exact same permissions? Are there permissions that won't be allowed? Only you can answer that.