Tbh league rankings are such nonsense. The data is broadly quite objective and can be manipulated to make some universities look much better than they actually are. I would consider league tables, but only as a minor factor and they are certainly not something to be worried about.
To be honest in most lines of work the university you attend doesn't matter in the grand scheme of things. Of course going to Oxford is going to give you much better graduate prospects than some far off university, but in general terms of employability, the rankings themselves don't matter.