Add Admin menus or submenus depending on conditions

I managed to find a solution:

File 1:

//Count the number of active plugins whose Author is "My Brand", and store the number in a global variable.

    $GLOBALS['mybrand_active_plugins']=0;

    if (!function_exists('get_plugins')){require_once ABSPATH.'wp-admin/includes/plugin.php';}
    $plugins=get_plugins();

    $activated_plugins=get_option('active_plugins');

    foreach ($activated_plugins as $p){           
        if( (isset($plugins[$p])) AND ($plugins[$p]['Author']=='My Brand')){
            $GLOBALS['mybrand_active_plugins']++;
        }            
    }   

// Add menus on sidebar

    if($GLOBALS['mybrand_active_plugins']<2)
    {
        function sub1_setup_menu()
        {
            add_menu_page('Sub 1','Sub 1','manage_options','sub1','sub1_admin_page');
        }
        add_action('admin_menu','sub1_setup_menu');
    }
    else
    {
        function sub1_setup_menu()
        {
            if (empty($GLOBALS['admin_page_hooks']['My Brand'] ) ){
            add_menu_page('My Brand','My Brand','manage_options','mybrand','mybrand1_admin_page');
            }
            add_submenu_page("mybrand","Sub 1","Sub 1",'manage_options',"sub1","sub1_admin_page");
            remove_submenu_page("mybrand","mybrand");
        }
        add_action('admin_menu','sub1_setup_menu');
    }

// Initialize Brand and Plugin Admin Page

    function mybrand1_admin_page()
    {
        echo "<h1>My Brand Plugins</h1>";
    }   

    function sub1_admin_page()
    {
        echo "<h1>Sub 1</h1>";
    } 

File 2:

//Count the number of active plugins whose Author is "My Brand", and store the number in a global variable.

    $GLOBALS['mybrand_active_plugins']=0;

    if (!function_exists('get_plugins')){require_once ABSPATH.'wp-admin/includes/plugin.php';}
    $plugins=get_plugins();

    $activated_plugins=get_option('active_plugins');

    foreach ($activated_plugins as $p){           
        if( (isset($plugins[$p])) AND ($plugins[$p]['Author']=='My Brand')){
            $GLOBALS['mybrand_active_plugins']++;
        }            
    }   

// Add menus on sidebar

    if($GLOBALS['mybrand_active_plugins']<2)
    {
        function sub2_setup_menu()
        {
            add_menu_page('Sub 2','Sub 2','manage_options','sub2','sub2_admin_page');
        }
        add_action('admin_menu','sub2_setup_menu');
    }
    else
    {
        function sub2_setup_menu()
        {
            if (empty($GLOBALS['admin_page_hooks']['My Brand'])){
            add_menu_page('My Brand','My Brand','manage_options','mybrand','mybrand2_admin_page');
            }
            add_submenu_page("mybrand","Sub 2","Sub 2",'manage_options',"sub2","sub2_admin_page");
            remove_submenu_page("mybrand","mybrand");
        }
        add_action('admin_menu','sub2_setup_menu');
    }

// Initialize Brand and Plugin Admin Page

    function mybrand2_admin_page()
    {
        echo "<h1>My Brand Plugins</h1>";
    }   

    function sub2_admin_page()
    {
        echo "<h1>Sub 2</h1>";
    } 

I don’t know if this can be achieved in a shorter way but it works.