There is no need to reset the SIP trunk or the GW when doing changes in the CSS itself, and the order of the partitions in the CSS only is relevant when two or more equally good matches exist.
The order of the partition decides it, if you have added that partition below the existing partition you won't have any effect on Incoming calls for example you have a translation pattern and a directory number with same length and you changed the order of the partition that will actually affect the inbound calls so make sure that you don't have any overlapping patterns associated to that additional partition you are adding, also for any changes to the SIP trunk to be effective (This is not required in your case as long as you are not changing the CSS in SIP trunk) you have to reset the SIP trunk which will actually reset the trunk for a while and any SIP signalling in progress will be dropped (Remember these calls I am talking about which are not established there two way RTP communication)
There is no need to reset the SIP trunk or the GW when doing changes in the CSS itself, and the order of the partitions in the CSS only is relevant when two or more equally good matches exist.
