Ini is a great stat....but the value if ini doesn´t matter at all. It is enough to have 1 point more Ini than the given oponent to benefit from it.
Combines with lightning reflexes and GW it tends to become a too important stat, because LR cancels out the INi modification of GW. And suddenly the Ini 5 white lion ncluding the GW malus, hits at the same time as a spear elf. The +1 to hit is by far surpassed by the strength bonus the GW delievers.
For all the rest, Ini works as intended. But the lower your Ini get´s the less important the stat becomes, because you will hit last against most other oponents. Only fighting against regulart GW units INI has some worth then.
In my opinion there is no need to rework InI. Only some issues with GW and lightning reflexes that seem to be unbalanced.
anyway, there are units without LR and GW that can hit just as hard but also bring durability to the table as such you need to present a way better argument than "LR + GW is too strong".
conclusion, if GW+LR is too strong than so are those units that can do the same without LR+GW, especially if they are more durable, and I can name atleast 8 units without looking into the army books that can hit just as hard at very good Ini with just their sheer amount of attacks or simply due to high base stats.