Ele has options. Reliable options, that's a different story.
Ill break down those "options" into sections of each moment of... lets say EvO
Early Game-
3 Earth start< first earth to tower+ other two to miners< cap tower for +40 if opponent archer starts/stall if sword with one earth< after archer begins the approach or swords become troublesome, move back to base with earth and garrison or morph as applicable and begin eco stall if pressured or build as normal if not.< aim for tree shortly after first row of gold is filled up (weak earths/miners are to be placed on mana)< follow tree with another and then a fire
Early-Mid
Follow with an upgrade and another fire as applicable< another tree and another fire at your discretion< an extra water and upgrades as you see the need (water is for scorch defense)
Mid
HEAVILY DEPENDENT ON HOW MUCH PRESSURE AND WHAT ARMY COMP YOU FACE make the following as you should see fit: V(s) w/clones (to steal spears and merics ((this allows you to use your scorps' poison to the fullest extent.)), Cycloids w/tornado x2
Mid-Late
Keep up the pressure by pushing for ts1 and more V's and/or waters as you see fit.
Late
Send your trees to die as they are useless pop space and should be replaced with waters and maybe airs if the situation rewards such.
Charrogs seem relatively lack luster in general against the order player that plays correctly seeing how charrog isnt as cost efficient with requiring one to remove both a fire and an earth to build.
You have many more options when attempting to go into trees as opposed to the other as you have the ability to go into your trees whilst still being able to keep your ranged units, thus granting you a tank, a seige factor, DOT with upgrades that doesnt need to be activated and is passive, your ranged unit possibility to go into scorch.
In the process of creating a charrog you have less cost effective options with increased micro requirements. To illustrate what im trying to convey.
Charrog:
Pros-
Extremely tanky
Burn ability cannot be cured
Cons-
Burn is Significantly less influential damage output wise as opposed to that of poison DOT
Initial Dps from melee is relatively insignificant for the cost
Requires one to sacrifice a ranged unit and one earth
Tree:
Pros-
Costs less
Death blossom snipes weakened units (and restores a sliver of health that isnt really worth 2 grains of salt but hey... its a thing.)
Spawns units that respawn shortly after death
Units that spawn can deal poison DOT
Cons-
Less Tanky than Charrog
must remain still and rooted to be of use.
Thats basically it.