If I recall automotive lore, Ford started the 3.5L ecoboost by taking a Mazda 3.0L diesel design, stroking it, gasifying it, slapping Warner turbos on it, and keeping the over-built lower end. The problems with the original engine (which I have the first year of in my truck) was timing chain stretch in 2011 (fixed in 2012 and anybody who got OEM work done on their 2011), phasers wearing and sticking, the timing chain guide wear from flopping timing chains, the gasket failing on the fuel pump thereby allowing the fuel pump to fill the block with fuel (whoops), carbon build-up on the backside of the intake valves from a lack of fuel washing the intake valves off, and slugging the engine with water from the intercooler, hydrolocking the engine and blowing a rod threw the block.
When we first heard about the slugging problem, over on the F150 forums back in 2011, I suggested everybody drill a 16th in hole at the bottom left of their intercooler as all turbo engine from before tree-huggers cared and racing engines have bleed holes in their intercoolers to blow water vapor out the bottom so as to not slug the engine with water under the right conditions. Ford cannot drill holes because of environmental concerns, but we can.
In my case, I added a big catch can and rerouted all of the engine's crankcase vent to that rather than dumping those gasses back into the intake, thereby limiting the carbon on the intake valves issue.
In 2018 Ford redesigned the 3.5 completely solving the original problems.
Anyway, the 2.7L I believe is a complete copy of the new 3.5L except it has a smaller, lighter block. Because of the lighter weight block somewhere somebody thought that it should not be rated the same as the 3.5L and (even if it is the same block as the larger 3.5L), I'm guessing for marketing reasons likely held the big tow numbers off for the 3.5L.
Anyway, my prone-to-explode (not really) original ecoboost 3.5L has been a real workhorse in my F150 and I'd be tickled pink to have another—especially since I know how to mitigate the flaws of the original design and the redesign is turning out to be claw-hammer reliable.