The leen letters have a timing of longer than one vowel count, but shorter than two vowel counts (maddam-mā). Do..

Bismil-Lāhir-Rahmānir-Raheem.

’Assalāmu ‘alaikum rahmatul-Lāhi wa barakātuh,

The leen letters have a timing of longer than one vowel count, but shorter than two vowel counts (maddam-mā). Do the other letters with the characteristic of ’arrakhāwah have the same timing when sākinah?

Jazākal-Lāhu khairā.

Salāmun ‘alaikum wa rahmatul-Lāhi wa barakātuh.

Answer

Wa alaikum assalaam wa rahmatullahi wa barakatuh,

We cannot compare vowel timings to saakin letter timings because the system is not the same.  One is a specific unit based on a single vowel count, the other (saakin letter timings) is based on the ear and a mastered teacher explaining if it too long or too short.  We can tell from the question that you understand that different groups of saakin letters have different timings, but these timings are not based on the count of a vowel.  The same thing holds true for the timing of the ghunnah- it cannot be compared to vowel counts because it is not based on vowels, but on the trained ear.

Wa iyyaakum.  Wa alaikum assalaam wa rahmatullahi wa barakatuh.