Is this over kill?

[Mumma]

In the last week I have found myself with three new bettas bringing my total to 7! I had space in an empty 8g tank for one but the other two had to spend two days in vases (I feel bad about that ). Today I set up my 26g/100L tank. It's a 3 foot long and skinny tank. I've never had a divided tank before so I just want to check a couple of things. I have the tank divided into 6 sections (15cm x 30cm x 38cm) of nearly 4.5 gallons each. I used book report binders and plastic craft mesh to make dividers. They go from the very top of the tank to the very bottom buried in the PFS substrate. They are a nice snug fit. Is this sufficient?
I am planning on a small air driven sponge filter in each section and the heater placed in one of the middle two sections. Is a sponge filter in each compartment too much? I have 2 running at the moment and the surface aggitation isnt much. I would rather have extra filtration then too little. I just don't want it to make my bettas uncomfortable.
Any thoughts are welcome.

[Olympia]

Maybe space out your filters a bit, since there is water flow between the compartments. Maybe 2 filters would be good.
I know some people put little canopies along the tops of the divider as an extra precaution, so if a betta jumped it'd hit the canopy instead of possibly going over to the other side.

[Mumma]

Thanks for the reply. I think I'm going to have 3 filters in compartment 1, 3 & 5 and see how they go. The tank has half glass tops and half mesh tops with the dividers to about .5cm from them. Thanks for the suggestion!