Whether or not I would do this would be the penalty if missing the AMS-LHR flight. If booked with cheap points and you had a "plan b", I would risk it. In theory, this should be fine. If you have the ability to us e-gates at T5 then it is just down to bags. They will not be quick but in normal times 30 minutes is typical I think. However, I did wait 1h15m for bags on my last go at T5 luggage, it was a complete mess. There was mention of free bus upthread, I honestly had not seen that before. The transfer via train kinda sucks and is a bit time consuming. It can easily eat up 45 minutes so if you can hit that bus, probably is better. Worse case, I think you are at T4 in 2 hours given those numbers. That is tight but doable, particularly if you have fast track at T4. Without bags, it is pretty easy.