Yes, as long as the scsi host adapters use different id's, or different scsi devices if you use an A2090 and a GVP scsi card.
I don't know if you can change the scsi host id on an A2090. Some scsi adapters you can, but many you can't.
Since you can have up to 7 scsi devices (hard drives) on one scsi controller, why would you want to use more than one controller card.