So I wonder whether you are not appreciating what an i Ironman is and what its about. its not all about smashing yourself into smithereens.
More specifically you are training on a indoor trainer and so those workouts are efficient.
Image your FTP is 200, holding 100watts is easy right? now imagine your FTP is 400, holding 200 watts is easy. when you start looking at the analytics you want to work on the strength at the beginning of the programme so a stronger set of legs when you start to build endurance as its hard to build power on tired legs.
Another way… if you are strong you can endure lighter efforts for longer?
When it comes to the run as with you the run sessions are along the same line if you look at the plan you have intervals at the beginning of the week, ( same for the run) tempo ( same for the Run) long base ride ( same with the run so the principle are the same but I assume the volume is paired down to account for the difference in distance. The difference that I feel is overlooked is that the running isn’t a paired down version cycling as the resistance and loads are very different.
I use TrainAsOne for the run workouts, its free-ish and I plug in the session days that I want and then use that run programme as its created: Referal link
Now that sets reasonable sets but it also watches the bike and swims and then on a Saturday it calculated an 11 minute run as its seen the TSS for the bike and the other runs and decided that I need something easy. the more you run the more it learns about your recovery and then the more effort it assigns you.
I can tell you that the plan works and compared to bought in coaching its a bargain and the cycling is geared around a ramp test so little margin for error. if you want to get round the course this will be fine. if you ultimately want to nail a kona slot and you are in good shape then I would start looking at commercial coaching arrangements because volume doesn’t equal performance at Ironman. its more about learning to recover