I think that's an even better Phase 1 strategy.

Instead of immediately creating 500 topic pages, create one comprehensive quiz page per subject and make it clear that it covers all major topics. Later, you can split each topic into its own dedicated page and link them together.

For example:

Programming
│
├── PHP Quiz
├── Java Quiz
├── Python Quiz
├── JavaScript Quiz
├── SQL Quiz
├── C Quiz
├── C++ Quiz
├── C# Quiz
├── HTML Quiz
├── CSS Quiz
├── Linux Quiz
├── Git Quiz
├── React Quiz
├── Node.js Quiz
├── Laravel Quiz
└── Django Quiz

Then, on the PHP Quiz page, include a section like this:

PHP Quiz Topics Covered

This PHP Quiz contains multiple-choice questions from all major PHP concepts, including:

PHP Introduction
PHP Installation & Environment
PHP Syntax
PHP Variables
PHP Constants
PHP Data Types
PHP Operators
PHP Expressions
PHP Strings
PHP Arrays
PHP Conditional Statements
PHP Loops
PHP Functions
PHP Scope
PHP Superglobals
PHP Forms
GET & POST
Sessions
Cookies
File Handling
Date & Time
Regular Expressions
Exception Handling
Error Handling
Object-Oriented PHP
Classes & Objects
Inheritance
Interfaces
Traits
Namespaces
Magic Methods
MySQLi
PDO
CRUD Operations
Prepared Statements
Transactions
JSON
XML
REST API
cURL
Security (SQL Injection, XSS, CSRF)
Composer
Autoloading
Laravel Basics
PHP 8 Features
Advanced PHP

This approach has several SEO benefits:

It naturally includes many relevant keywords without keyword stuffing.
It demonstrates topical breadth to both users and search engines.
It prepares the page for future expansion.

Later, when you create PHP Variables Quiz, PHP Arrays Quiz, etc., you can turn each item in the list into an internal link. This creates a strong topic cluster without having to redesign the page.

I would organize the entire Programming section like this

PHP
Python
Java
JavaScript
TypeScript
C
C++
C#
SQL
HTML
CSS
Bootstrap
React
Angular
Vue.js
Node.js
Express.js
Laravel
CodeIgniter
Django
Flask
Spring Boot
Git
GitHub
Linux
Bash/Shell Scripting
Data Structures
Algorithms
Operating System
Computer Networks
DBMS
MongoDB
Oracle Database
MySQL
PostgreSQL
Docker
Kubernetes
DevOps
REST API
GraphQL

One suggestion

When you create these subject pages, make sure the topic list reflects what users actually expect to learn. For example, on the PHP page, don't just list topics—briefly state that the quiz includes beginner, intermediate, and advanced questions across all of them. This improves user confidence and gives you a natural place to introduce future topic-specific quizzes through internal links. Over time, this can become a very strong SEO structure.