ADS7953: Reduce interface pin count by connecting one CLK and/or SDI and/SDO to multiple ADCs

Part Number:ADS7953

For added diagnostic on a PCBA I like to add several ADS7953 (15pcs).

Is it possible to reduce the interface pin count to the controller (FPGA). For example connect all CLK lines, SDI and SDO lines to three FPGA pins and 15 CS selections pins. This would reduce the pin count on the FPGA from 60 to 18.

A sample rate of 1Hz for each input is enough for diagnostics purposes.

Taking SI in to consideration: one bus line, no/short stubs to the ADCs pins.