It's not a terrible strategy to keep your bet sizes consistent overall - but its not necessarily a great strategy either.
The reason being that position and hand strength are really only two factors in the outcome of the hand. Remember that the real game happens at the flop. Pre-flop strategy should also involve how many other players are betting into the pot, and how frequently those players are limping. It also depends on where you see the hand going - which street do you see the hand ending?
For example - if you have A 2 suited, mid position, you may see the hand flop: 1) You flop an Ace. (2) You miss the flop. (3) You flop a flush draw (4) you flop a monster like A A X, or A 2 X, or the flush pops right there.
In example 1 and 2, the hand is really only going to go well for you if it ends at the flop. Chances are if you are going into the turn you're either up against a draw, a better pair, or a monster. In example 3 you need to be able to freely bet your odds on catching your draw (3:1). In 4 you need to be able to keep money going into the pot.
In all of these examples you have the minimal losses vs. the maximum gain IF the pot on the flop is fairly small. A big pot in the first three examples is high risk for you, and in the fourth example is high risk for the other players. So from middle position, a 2x Blind raise is probably a better option than a 3x Blind raise (assuming you want to play A 2suited). But the validity of this strategy changes if you have a ton of limpers - in which case you probably want to fold, unless you have a big chip lead, and then you're playing to the absolute nuts only. It also changes if you have more calling power. You have more calling power from late position so you can play for the turn (2x being a good number for that), or play big on the flop or even steal pre-flop (4, or even 5x Blind raise might be good for that). I wouldn't really recommend playing A 2 early position, but if you have a chip lead and want to beat someone up you may want to do a 4x or 5x Blind raise just to ensure you're either stealing or keeping the number of players going to the flop to a minimum.
So it all varies based on intentions.