SOAP UI assert on JSON Response check not 0

Thank you to: https://thetestsuite.wordpress.com/2013/09/30/soapui-groovy-slurping-json-in-script-assertions/

Script assert....

//imports
import groovy.json.JsonSlurper

//grab the response
def ResponseMessage = messageExchange.response.responseContent
//define a JsonSlurper
def jsonSlurper = new JsonSlurper().parseText(ResponseMessage)

//verify the slurper isn't empty
assert !(jsonSlurper.isEmpty())

//verify the queue size is not 0
assert jsonSlurper.lastRecordedQueueSize != 0

//verify the queue size is not null
assert jsonSlurper.lastRecordedQueueSize != null

Can't figure out the bonus point question though (yet) - can't see how to verify 1 assert from one response against the value of another assert from another response - playing with Groovy script but anyone got any tips on this would be amazeballs!

//imports
import groovy.json.JsonSlurper

//grab the response
def ResponseMessage = testRunner.testCase.testSteps["Local Cluster During Flush"].testRequest.response.responseContent
def oldResponseMessage = testRunner.testCase.testSteps["Local Cluster With Queued Data"].testRequest.response.responseContent
//define a JsonSlurper
def jsonSlurper = new JsonSlurper().parseText(ResponseMessage)
def oldJsonSlurper = new JsonSlurper().parseText(oldResponseMessage)

//verify the slurper isn't empty
assert !(jsonSlurper.isEmpty())

//verify the queue size is not 0
assert jsonSlurper.lastRecordedQueueSize != 0

//verify the queue size is not null
assert jsonSlurper.lastRecordedQueueSize != null

// Convert old size String to an Integer
def oldSizeStr = oldJsonSlurper.lastRecordedQueueSize
oldSizeStr = oldSizeStr.substring(0, oldSizeStr.indexOf("(")).trim()
oldSizeStr = oldSizeStr.replaceAll(",", "")
int oldSize = oldSizeStr.toInteger()

// Convert new size String to an Integer
def newSizeStr = jsonSlurper.lastRecordedQueueSize
newSizeStr = newSizeStr.substring(0, newSizeStr.indexOf("(")).trim()
newSizeStr = newSizeStr.replaceAll(",", "")
int newSize = newSizeStr.toInteger()

// Compare old and new sizes
assert newSize < oldSize