Please read the two lines in green on my last post.

If one person spends 5K on mining equipment, or 20 people together spend 5K each on mining equipment, they will not magically get extra Bitcoins from nowhere.

So if one person spends 5K on equipment and joins a pool, any pool, they will get almost the exact same number of BTC's as joining up with 20+ other friends. Maybe 0.01% less (if the pool keeps the block generation fees) and maybe a percent or two less if the pool charges for their bandwidth costs and server(s) rental/purchases. But the same extra, hidden, costs if not more would exist for 20 people mining together.