RE-MT missiles question

I have 2 ways of using these missiles-

1st way is treating them as fighters, with 3 turns endurance. Have to use 1
turn of endurance for each movement (24 MU), can use a secondary move of upto
12 MU, using extra 1 endurance. For every extra endurance the missile
has when attacking the ship/target, it gets a extra +1 against PDS
(represents using all it`s drive power in overload to sprint attack against
the target). 6 MU engaugement envelope.

2nd way is that they have 3 drive settings. On endurance setting, they have 3
turns of movement, can move 24 MU per turn (same as normal sml`s), and a
engaugement envelope of 6 MU. On normal settings, they have 2 turns of
movement/endurance, a range of 36 MU per turn (same as er sml`s), and a
engaugement range of 5 MU. On sprint setting, they only have one turn of
movement, can move upto 48 MU in that turn, and have a engaugement range of 4
MU. When used in this setting, they are intercepted as heavy fighters
(5
or 6) due to the greater closing speed. The drive setting used must be decided
before launch (noted as either a E (endurance) or S (sprint) next to missile
launched symbol). If no setting is specified, assumed to be launched
on normal setting (2 turns, 36 MU per turn). In turns/movement, used
exactly like fighters.

You may have noticed that I use comparisons to sml`s. This is because a sml
salvo has a range of 24 MU, a endurance of 1 turn, and a dammage of upto
6D6. A MT missile has 1/3 the dammage, 3x the range, but only 18 MU per
turn
(if using the same drive/tech in both missile systems, the range should
be the same per turn). This does not include the fact that sml`s are a harder
point defence target than MT missiles (in my experiance).

> 1st way is treating them as fighters, with 3 turns endurance. Have to

This suggests another alternative to me. Say missiles have an endurance of 6.
They pay one point of endurance for every 12" of movement (up to 24 MU in the
primary and 12 MU in the second movement phase)