I did find something interesting on the 'strength size' part of that though...
I'll summarize, then post the study and another graphic I found where the study was being discussed.
There does seem to be ‘some’ sarcoplasmic hypertrophy (as in, more cytoplasm without myofibrilliar size increases), apparently, this can happen first, for a while, then once the domain is maxed, THEN nuclei are added and actual contractile increases occur. The higher volume may have increased cytoplasm much more with equal strength gains, later, if able, the subjects would have then increased myo-nuclei numbers and fibril hypertrophy would occur and THAT would lead to a strength increase. This is not to be confused with swelling or fluid changes, which may or may not also accompany resistance training. This is intra-cellular cytoplasm increases (aka sarcoplasmic hypertrophy) This cannot continue long term without myo-nuclei additions and concurrent fibril hypertrophy, but seems it can be predominant even up to 3 months. It appears to be a ‘stair step’ phenomena as described below. Higher ratio of cytoplasm, leads to additional nuclei, fibril hypertrophy ‘catches up’, then cytoplasm increase, then fibril, etc.
https://journals.lww.com/.../Early_Phase_Satellite_Cell...
Below a couple quotes from the study
Myonuclear domain is the volume of cytoplasm within the multinucleated skeletal muscle fiber
In contrast, Kadi et al. reported a 17% increase in fiber cross-sectional area (CSA) of the quadriceps muscle group of young men after 3 months of resistance training, with a significant increase in MND and no change in myonuclear number (17).
Based on studies such as these, a “ceiling” for MND has been proposed, above which the addition of more myonuclei is required (17). Existing myonuclei are not usually operating at maximal capacity at baseline and have the ability to increase protein synthesis and cytoplasmic volume up to some threshold (17). O'Connor et al. have suggested that muscle hypertrophy consists of several phases in which early upregulation of transcription and translation in existing myonuclei is then followed by SC activation, proliferation, and potential incorporation (29).