(I started posting the below as a top-level comment, but in the end it arrived at the same point as yours, so leaving it as a reply…)
In Indian/Sanskrit literary theory (poetics), in the discussion of figures of speech (rhetoric, etc), similes are called upamā ("her face is like the moon", etc). The discussion of it in the literature is extensive and would fill several volumes (and I hardly know anything), but one thing recognized early is that in a simile/analogy, there needs to be a sādharaṇa-dharma, a shared property: the point is that there's something in common ("her face is beautiful, like the moon") while of course there is going to be a lot that is not (the intended meaning is not "like the moon, her face is pockmarked, full of craters", etc). In any given instance, this intended shared property may either be stated explicitly, in which case the simile is called "complete", or left implicit, in which case it's called "partial". Both can be highly effective.
In the context of this post, it seems that when making an argument, it may help for the analogy to be "complete": actually spell out what you intend by the analogy. Also, to echo the comment by @munificent, it is worth remembering that figures of speech are very effective as poetry, but poetry requires a sensitive and sympathetic reader (sahṛdaya). The same rhetoric can fail when used in argument with an unsympathetic audience.
In Indian/Sanskrit literary theory (poetics), in the discussion of figures of speech (rhetoric, etc), similes are called upamā ("her face is like the moon", etc). The discussion of it in the literature is extensive and would fill several volumes (and I hardly know anything), but one thing recognized early is that in a simile/analogy, there needs to be a sādharaṇa-dharma, a shared property: the point is that there's something in common ("her face is beautiful, like the moon") while of course there is going to be a lot that is not (the intended meaning is not "like the moon, her face is pockmarked, full of craters", etc). In any given instance, this intended shared property may either be stated explicitly, in which case the simile is called "complete", or left implicit, in which case it's called "partial". Both can be highly effective.
In the context of this post, it seems that when making an argument, it may help for the analogy to be "complete": actually spell out what you intend by the analogy. Also, to echo the comment by @munificent, it is worth remembering that figures of speech are very effective as poetry, but poetry requires a sensitive and sympathetic reader (sahṛdaya). The same rhetoric can fail when used in argument with an unsympathetic audience.