Validator doesn't give warning when a natural=scrub and natural=wood areas overlap

[anonymous]

What steps will reproduce the problem?

1. Just create two areas that overlap, and tag one of them as natural=wood and the other as natural=scrub
2. The validator does work when both are scrub or wood
3. Another combinations that give problems are wood or scrub overlapping wetland or water

What is the expected result?

The validator should give a "Overlapping natural areas" or similar

What happens instead?

No warning in the validator.

Please provide any additional information below. Attach a screenshot if possible.

Relative:URL: ^/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2020-01-02 22:34:59 +0100 (Thu, 02 Jan 2020)
Revision:15628
Build-Date:2020-01-02 21:52:31
URL:https://josm.openstreetmap.de/svn/trunk

Identification: JOSM/1.5 (15628 en_GB) Linux Ubuntu 19.10
Memory Usage: 411 MB / 3504 MB (189 MB allocated, but free)
Java version: 11.0.5+10-post-Ubuntu-0ubuntu1.1, Private Build, OpenJDK 64-Bit Server VM
Screen: :0.0 1680x1050, :0.1 1680x1050
Maximum Screen Size: 1680x1050
Java package: openjdk-11-jre:amd64-11.0.5+10-0ubuntu1.1
Java ATK Wrapper package: libatk-wrapper-java:all-0.35.0-3
fonts-noto: fonts-noto:all-20181227-1
VM arguments: [-Djosm.restart=true, -Djava.net.useSystemProxies=true]
Dataset consistency test: No problems found

Plugins:
+ apache-commons (35092)
+ ejml (35122)
+ geotools (35169)
+ jaxb (35092)
+ jts (35122)
+ opendata (35280)
+ todo (30306)
+ utilsplugin2 (35248)

Last errors/warnings:
- W: No configuration settings found.  Using hardcoded default values for all pools.

[GerdP]

All overlapping areas are flagged when "Other" level is enabled.
I think it was quite normal to map a natural=water area inside or overlapping a natural=wood in the past, but maybe this is no longer wanted?
What about overlapping landuse areas. Same case?
Simple approach for natural: Change rule

area:closed:areaStyle[tag("natural") = parent_tag("natural")] ⧉ area:closed:areaStyle[natural] {
  throwWarning: tr("Overlapping Identical Natural Areas");
}

to

area:closed:areaStyle[natural] ⧉ area:closed:areaStyle[natural] {
  throwWarning: tr("Overlapping Natural Areas");
}