Normally if you have a LOB column in a table shareplex DOES NOT allow you to use horizontal partition for this table
Shareplex horizontal partitioning on tables with LOB is not allowed
Administration Guide page 106 mention a table with LOBs cannot be configured for Horizontally partition.
Shareplex Administration Guide page 106 mention a table with LOBs cannot be configured for Horizontally partitioned replication and the workaround is to setup up vertical partitioning on this table first.
This way the LOBs column is not seem by shareplex. Then set up shareplex horizontal partitioning for the table.
NOTE - the Lobs column is not replicated as the vertical partitioning takes it out of replication