This is about as close as I can get creating a work-around in CSS.
The code will change your paragraph spacing to be the same as the line height, hide images and captions on your archive page posts (so that they don't get chopped in half) and set the post entry section to be a specific height (a multiple of your line height). It will probably break some sentences mid way through which is unavoidable but it might be worth a try.
The only other option is far more hands on and would involve going through all previous posts and placing all the text you want to feature on the archives page in a new div element with its own class which you can then target with CSS.
Here's the code anyway:
.entry p {margin:0 0 1.5em;}
body.archive .post .entry {height:210px;}
body.archive .post .wp-caption, body.archive .post img {display:none;}