I'm not sure how much power the "Raspis" need. The thing manages just 2.4A max. per port if you use several at the same time. Have a look at the specs below:
https://www.anker.com/products...
To be on the safe side, I wouldn't recommend it.

I would say that the anchor is easily enough for 3 Raspis. See here:
https://www.pidramble.com/wiki...

Yes, that's enough for 3 Raspberry Pi 3B+ (power supply delivers 6.4A max/2.4A per port).

I can agree with schLEIMER. Depending on how much power the Raspis need, the device may not be able to distribute the power over three pieces.