And no, I don't "now" have to speculate four -- my original idea was always for four, but in absence of listing a number you assumed four. However you can assume three helicopters if you want either. The point is that the greater helipad affords greater flexibility for helicopter or VTOL UAV operations from the ship.
Well, we do not know if the 2450 ton ship is the one that the Navy is supposedly interested in (could the Navy version be bigger, or maybe it might be smaller?), nor do we know if the 2450 ton displacement is for standard or full displacement (especially considering the model trimaran's dimensions is very similar if not a little bit greater than that of the Independence class LCS which displaces over 3000 tons full)...
If displacement is the primary objection to the conops I've laid out, I think that is a viable counter to make, but it doesn't by any means sink it as we do not know what the displacement of the Navy's supposed interested version will be, and I think we also have a reasonable case to wonder whether the displacement of the model that they've shown is for its full displacement or not.
I would also argue that there is not necessarily a correlation between the number of helicopters that a ship can support with its displacement, as the design of different ships can afford for different use of displacement for different purposes -- endurance vs armament vs helicopter embarkment vs sensors vs whatever.
I think it is reasonable to consider whether they would design a ship with a significantly larger than normal helipad to also have designed a greater ability to accommodate a faster pace of helicopter operations as well. So even with the real ship displacing significantly less than an 054A I do not consider the prospect of a greater helicopter embarkment and operation capability to be an unreasonable one.