I'll do just that. I was just worried that if I added 1 or 2 more loaches later on, it may stress out the existing ones since I didn't introduce them all at the same time.You can add two more (if you are planning on a bigger tank later), but you don't have to rush into this.
Five is a reasonable shoal, and you can wait until you see a clown you cannot resist, this will happen sooner or later. (this is what I did, I have six right now)
Is it okay to get clown loaches in even numbers (say 6)? I read that its better to get odd numbers like 5 or 7, but not sure if this is true - do your 6 clowns school together all the time? Are they shy during the day?
I personally do not believe in odd numbers.
My pattern is that I see all six as a single group in the mornings (until about noon). Evenings I mostly see a gang of three (the same ones), the others do come out for food and occassional walk. By about 10pm they all retire.
Adding more later is not a problem, as long as they are smaller than your largest one.