for what it's worth...the only knots you need to know on the national firefighter certification test are:

Figure 8
Figure 8 on a Bight
Figure 8 follow-through
Bowline
Becket (or Sheet) Bend
Half-Hitch
Clove Hitch

I use all of these but the Bowline all the time. Just last night, we did an auto extrication - car on its side - and we used rope to secure the vehicle -
2 huge metal stakes into the ground, either side of the vehicle, first clove hitch and 2 half hitches to the one stake, rope up, over, around the frame, back through two 8's on a bight, which acted as a ratchet, and then to the other stake, clove & 2 half hitches there. Rope was so tight you could walk on it. Car was STABLE.

I've found that, with few exceptions, if you can't do it with a variation on the figure 8, maybe you shoudn't be doing it.