TRY NUMBER 1:
Globally:
new timid1, timid2;

public OnFilterScriptInit() {
	timid1 = SetTimerEx("test2", 10000, 1, "ii", 2, timid1);
	timid2 = SetTimerEx("test2", 5000, 1, "ii", 1, timid2);
}

public test2(number, timid) {
	printf("%d, %d", number, timid);
	KillTimer(timid);
}

Always outputs 0 for both, doesn't kill the timers since there is another timer with id 0 (in gamemode).

TRY NUMBER 2:
public OnFilterScriptInit() {
        new timid1, timid2;
	timid1 = SetTimerEx("test2", 10000, 1, "ii", 2, timid1);
	timid2 = SetTimerEx("test2", 5000, 1, "ii", 1, timid2);
}

public test2(number, timid) {
	printf("%d, %d", number, timid);
	KillTimer(timid);
}

Always outputs 0 for both, doesn't kill the timers since there is another timer with id 0 (in gamemode), just like try number 1.

TRY NUMBER 3:
public OnFilterScriptInit() {
	new timid1 = SetTimerEx("test2", 10000, 1, "ii", 2, timid1);
	new timid2 = SetTimerEx("test2", 5000, 1, "ii", 1, timid2);
}

public test2(number, timid) {
	printf("%d, %d", number, timid);
	KillTimer(timid);
}

Will output 256 for call number one (every 10 seconds), 18392 for call number 2 (every 5 seconds).
Will not kill the timers.

TRY NUMBER 4:
public OnFilterScriptInit() {
	new timid1 = SetTimerEx("test2", 10000, 1, "ii", 2, timid1);
	new timid2 = SetTimerEx("test2", 5000, 1, "ii", 1, timid2);
}

public test2(number, timid) {
        new timer = timid;
	printf("%d, %d", number, timer);
	KillTimer(timer);
}

Will output 256 for call number one (every 10 seconds), 18392 for call number 2 (every 5 seconds).
Will not kill the timers. Same as with try number 3.