yep - you are correct but your explanation can be improved a little. English is very consonant forward and obviously has syllables that merge.

A non-IPA breakdown might look like...

tran-SI-shyun.

Always starting with a consonant and the "tion" merging into 1 syllable.

In Spanish syllables are usually vowel forward. so this word becomes:

trans -ic - i - ÓN.

4 syllables instead of 3.

Also - there's very little (possibly none?) dialectal variation in syllable length in Spanish. As you mentioned it's predictable. In english this can vary. Example word "general". In english it could be:

Ge-nu-rul

or

Gen-rul

In either case the dominate feature is the R starting the final syllable.

Spanish would be:

gen-er-AL

each syllable starting on the vowel (besides the first obviously) and there really isn't any variation in how this word is syllabicated.