SCCP and SS7, it’s the “same” thing (one is the name of the protocol, the other the name of the pysical channel)
the SS7 of 1 TS out of 4 E1 will carry enough signalling for the 4 E1’s.
If you have 8 E1s, you’ll need two SS7. The signalling of one circuit channel will be carried on either SS7, not necessarily the one located on its “4-E1s” group.
Is that answering your question ?