Pathfinder scientists also suggested some rocks at the Pathfinder site were conglomerates:

No, they didn't say that. they said:-

Surface pebbles may have been rounded by Ares flood waters or liberated by weathering of sedimentary rocks called conglomerates.

They also said:-

Sojourner ... discovered pebbles on the surface and in rocks that may be sedimentary...in origin

And what this means, IMHO, is:_

"We'd like to find actual conglomerates like on Earth, because this would be evidence for running water and for aqueous cementation processes that form new rocks from old pebbles, and multi-generation erosion-deposition-uplift-reerosion-reworking that would make Mars REALLY Earthlike. Unfortunately, all we can find is rounded pebbles which could have been rounded by a whole range of processes, only some of which involve liquid water. Looking on the bright side, we did see some oddly pitted rocks that in the right light looked as if they might be conglomerates with pebbles eroded out of the holes, even though every measurement made them out ro be volcanic. Nonetheless, if we emphasise the water aspects and also talk about wholly hypothetical precursor conglomerates, then it will make the water story sound better than the limited evidence would lead a sceptical observer to conclude. If we're lucky, some ill-informed net loon or a member of joe public will pick up on this and think that we've found more evidence for water on Mars."