The B-737 design is a few years older than the Tu-154 one.
If the very dense fog/low cloud at Smolensk was the main cause of the crash, the question is, would another plane with newest avionics made the difference?
Arrakis
Not only 737 is older in design, but this particular Tupolevs were similar age as LOT B737s. And 737s are not much superior in terms of safety record, especially if you discount cases of human error. Regarding avionics - both Polish VIP Tupolevs had cockpits completely refitted with Western avionics (Honeywell I think), they looked nothing like standard Tupolevs.