omnipobia and kosis are wasted as boss fights in simus

Why are simus so dull? Like i think is cool that they appear during the simus both i mapping and in the actual simus, but, wouldn't be better if they had a solo fight moment? Something like horde 13 ends with omniphobia alone, 14 with kosis and 15 with both of them. Right now they just appear to be one shooted or almost at best everytime.