I think it is a really bad idea to split a single project into artificial components and a bad precedent to set. Project IDs will no longer be consistent between published data and source systems, making reconciliation between different systems (e.g. IATI and local AIMS) more difficult. Activity-based reporting is an advantage of IATI over the CRS’s transaction-based reporting.
We have seen this a lot with donors breaking projects into multiple activities for each sector and country, where it significantly increases the amount of noise in the data. See for example Swedish projects here (Sweden is in the process of correcting this). The project beginning
SE-0-SE-6-5204006501- is broken into three activities (one for each sector code
72050) and many more activities when you consider the other countries this project is active in.
USAID recently corrected the same issue in their data and it made their data far more useful and usable.