Yes, I didn't really understand that. The three sensible connection choices for MIA to TLV are LHR, MAD (IB) and EWR (United/El Al). We can therefore rule out EWR since the MCT is 2 hours. MAD is typically 1 hour, the same as LHR T5, but some connections are 90 minutes including some TLV connections. If one wanted to be adventurous one can look at places like FRA, AMS, CDG or JFK, but I really doubt this is improving the experience or necessarily the MCT.

If booking a connection close to MCT one knows the downside is a risky/hassle-some connection, the upside is that generally it works, as it did here, and the journey is completed quickly. Moreover at LHR one can simply opt for a longer connection due to the frequency of services, something you can't necessarily do elsewhere given their service frequencies.