It's not possible in one step. You can select all the layers and drag them out to the correct duration, but this won't alter their positions to evenly spread them out. You can then use the Sequence Layers animation preset to redistribute them in time.
As Andrew said, not possible and if I may say so, on some level also a bit illogical - if there was such an automated fitting feature, it would have to be based on temporal scaling (time-remapping) and result in different playback speeds and the resulting usual problems with interpolating crooked frames. Not sure if that would ever be useful in any way to anyone... If, as you say, you have enough handle, why not simpyl extend them and then arrange them sequentially using the relevent keyframe assistant,m as Andrew already mentioned? This would be a 2 minute thing and give you way better results than anything you can do with time stretching...
Yeah... upon thinking about it, I realized my question sounded pretty illogical. Thanks though!
If I have properly understood your question...My reply is
A ) Make your composition duration not less than total duration of your 200 clips
B ) Select 1st Layer in timeline., and with 1st layer selected Press Shift and select last layer of your clip
Sequence layer window will open... uncheck Overlap see example.. click OK and your problem is solved.. I am not expert., but have some working knowledge... If I am wrong., I will try to learn from the possible correct reply youmay get