Terraform: Easier way to run a flexible number of objects - terraform

Question

Currently I have a powershell script that reads a yaml config file with all the objects I need created and creates a .tfvars file which contains all the variables, maps, lists of maps etc.
It would be something like the following:
global_tags = {
Provisioner = "Terraform"
}
resource_groups = {
myrg1 = {
location = "uksouth",
tags = {
ResourceType = "resourcegroup"
}
}
}
storage_accounts = {
mystorage1 = {
resource_group_name = "myrg1",
location = "uksouth",
account_tier = "Standard",
account_replication_type = "GRS",
tags = {
ResourceType = "storageaccount"
}
containers_list = [
{ name = "test_private_x", access_type = "private" },
{ name = "test_blob_x", access_type = "blob" },
{ name = "test_container_x", access_type = "container" }
]
}
The idea is to then pump each list of maps into each module to create the resources, e.g. main.tf would be just:
module "resourcegroup" {
source = "./modules/azure-resourcegroup"
resource_groups = var.resource_groups
global_tags = var.global_tags
}
module "storageaccount" {
source = "./modules/azure-storageaccount"
depends_on = [module.resourcegroup]
storage_accounts = var.storage_accounts
global_tags = var.global_tags
}
Also, an example of a simple module would be:
resource "azurerm_resource_group" "rg" {
for_each = var.resource_groups
name = each.key
location = each.value.location
tags = lookup(each.value,"tags",null) == null ? var.global_tags : merge(var.global_tags,each.value.tags)
}
The issue is that writing a complex module, say around storage account, isn't too bad if you are just feeding in all the params, but feeding in a list of maps and writing a module to read that list and create multiple flattened lists to perform say 15 different calls (to create containers, shares, network rules etc.) is very complex.
Obviously the reason I want to use for_each loops in the modules is so that my main.tf doesn't have to call the module multiple times with hard coded values for say 50 storage accounts.
Just wondering if I am missing an obvious way to create complicated multiples of each resource type ?
I appreciate I could do separate modules for containers, shares etc and break the complex maps down into simpler ones to pass to the additional modules, but I was trying to just have 1 storage account module that could handle anything and be fed by a complex list of maps so main.tf did not need editing, I could just control the config completely via a .tfvars file