I think Alfa did a smart thing with choosing the 1.9 engine they did, because it was common to the Vauxhall Vectra and Saab 1.9 Tid, so they took a lot of development worries out the equation for the big fleet runners at least.
I think if they do that again for the replacement, and pick at least one common engine in the line to keep a reliable reputation they'll do good again.
The same fiat 1.9 that was in the 147, 156, GT etc.? Essentially the original common rail engine with a cylinder missing and in 16 valve guise, an extra camshaft.
When the 159 was being developed it had to compete with Saab, Cadillac, Rover 75....none of which made it.
Also the traditional compact executives share is going down as more plump for SUVs and Alfa don't have one, Audi, BmW and Volvo have a full set of both, Benz have reshaped the B class towards the SUV angle, women don't care about the off road stuff and see the B as alternative to the X1
If it was me running the show, I would have the mito the 4C and a 250 bhp diesel Q5 competitor, nothing else makes any money or makes any sense, though I would still personally like a 159 or 166 type machine, it doesn't make any sense.
Look at Infiniti in the UK, ever seen ones that isn't a demonstrator?