Yes, but carefully. Good training plans incorporate multiple cycles. Weekly cycles (microcycles) will balance harder workout days with easy or rest days to follow. The fitness response/benefit happens during the recovery after a workout. Likely, 48 hours is the sweet spot for recovery, but everyone is unique and needs to factor in the usual suspects (age, fitness level, propensity for injury, stress, fuel, rest, sleep, sleep, and sleep). The real recovery comes during deep sleep [video] [article].
Longer cycles (mesocycles of 3 to 6 weeks) will have a gradual build up and then a lighter week for recovery for both the physical and mental aspects of long-term training. This is where you schedule your tune up races or vacations/travel.
The big picture planning (macrocycles) considers your running year where you schedule one or two “prime” races or events along with family and work commitments (this makes for interesting discussions). This prioritization is a key element for successful running and planning.
Yes, you can swap the days you schedule your tempo runs with your speed workouts and/or your long runs – but maybe not stacking your hardest workouts too close together. For you, maybe 36 hours is all you need after your long run on Saturday morning so you can do your speed work on Monday night and then tempo run on Wednesday morning. On a monthly scale, you can move your “easy” week to match your vacation. On an annual cycle you might take a 12 week plan and fit it into 13 weeks with a break (for vacation or a small taper heading into a tune-up race).